1 Known Problems with GNU Emacs
3 Copyright (C) 1987-1989, 1993-1999, 2001-2012
4 Free Software Foundation, Inc.
5 See the end of the file for license conditions.
8 This file describes various problems that have been encountered
9 in compiling, installing and running GNU Emacs. Try doing C-c C-t
10 and browsing through the outline headers. (See C-h m for help on
11 Outline mode.) Information about systems that are no longer supported,
12 and old Emacs releases, has been removed. Consult older versions of
13 this file if you are interested in that information.
15 * Mule-UCS doesn't work in Emacs 23.
17 It's completely redundant now, as far as we know.
19 * Emacs startup failures
21 ** Emacs fails to start, complaining about missing fonts.
23 A typical error message might be something like
25 No fonts match `-*-fixed-medium-r-*--6-*-*-*-*-*-iso8859-1'
27 This happens because some X resource specifies a bad font family for
28 Emacs to use. The possible places where this specification might be
31 - in your ~/.Xdefaults file
33 - client-side X resource file, such as ~/Emacs or
34 /usr/X11R6/lib/app-defaults/Emacs or
35 /usr/X11R6/lib/X11/app-defaults/Emacs
37 One of these files might have bad or malformed specification of a
38 fontset that Emacs should use. To fix the problem, you need to find
39 the problematic line(s) and correct them.
41 ** Emacs aborts while starting up, only when run without X.
43 This problem often results from compiling Emacs with GCC when GCC was
44 installed incorrectly. The usual error in installing GCC is to
45 specify --includedir=/usr/include. Installation of GCC makes
46 corrected copies of the system header files. GCC is supposed to use
47 the corrected copies in preference to the original system headers.
48 Specifying --includedir=/usr/include causes the original system header
49 files to be used. On some systems, the definition of ioctl in the
50 original system header files is invalid for ANSI C and causes Emacs
53 The fix is to reinstall GCC, and this time do not specify --includedir
54 when you configure it. Then recompile Emacs. Specifying --includedir
55 is appropriate only in very special cases and it should *never* be the
56 same directory where system header files are kept.
58 ** Emacs does not start, complaining that it cannot open termcap database file.
60 If your system uses Terminfo rather than termcap (most modern
61 systems do), this could happen if the proper version of
62 ncurses is not visible to the Emacs configure script (i.e. it
63 cannot be found along the usual path the linker looks for
64 libraries). It can happen because your version of ncurses is
65 obsolete, or is available only in form of binaries.
67 The solution is to install an up-to-date version of ncurses in
68 the developer's form (header files, static libraries and
69 symbolic links); in some GNU/Linux distributions (e.g. Debian)
70 it constitutes a separate package.
72 ** Emacs 20 and later fails to load Lisp files at startup.
74 The typical error message might be like this:
76 "Cannot open load file: fontset"
78 This could happen if you compress the file lisp/subdirs.el. That file
79 tells Emacs what are the directories where it should look for Lisp
80 files. Emacs cannot work with subdirs.el compressed, since the
81 Auto-compress mode it needs for this will not be loaded until later,
82 when your .emacs file is processed. (The package `fontset.el' is
83 required to set up fonts used to display text on window systems, and
84 it's loaded very early in the startup procedure.)
86 Similarly, any other .el file for which there's no corresponding .elc
87 file could fail to load if it is compressed.
89 The solution is to uncompress all .el files that don't have a .elc file.
91 Another possible reason for such failures is stale *.elc files
92 lurking somewhere on your load-path -- see the next section.
94 ** Emacs prints an error at startup after upgrading from an earlier version.
96 An example of such an error is:
98 x-complement-fontset-spec: "Wrong type argument: stringp, nil"
100 This can be another symptom of stale *.elc files in your load-path.
101 The following command will print any duplicate Lisp files that are
102 present in load-path:
104 emacs -batch -f list-load-path-shadows
106 If this command prints any file names, some of these files are stale,
107 and should be deleted or their directories removed from your
110 ** With X11R6.4, public-patch-3, Emacs crashes at startup.
112 Reportedly this patch in X fixes the problem.
114 --- xc/lib/X11/imInt.c~ Wed Jun 30 13:31:56 1999
115 +++ xc/lib/X11/imInt.c Thu Jul 1 15:10:27 1999
117 -/* $TOG: imInt.c /main/5 1998/05/30 21:11:16 kaleb $ */
118 +/* $TOG: imInt.c /main/5 1998/05/30 21:11:16 kaleb $ */
119 /******************************************************************
121 Copyright 1992, 1993, 1994 by FUJITSU LIMITED
128 + char* begin = NULL;
132 char* ximmodifier = XIMMODIFIER;
135 ret = Xmalloc(end - begin + 2);
137 - (void)strncpy(ret, begin, end - begin + 1);
138 + if (begin != NULL) {
139 + (void)strncpy(ret, begin, end - begin + 1);
143 ret[end - begin + 1] = '\0';
147 ** Emacs crashes on startup after a glibc upgrade.
149 This is caused by a binary incompatible change to the malloc
150 implementation in glibc 2.5.90-22. As a result, Emacs binaries built
151 using prior versions of glibc crash when run under 2.5.90-22.
153 This problem was first seen in pre-release versions of Fedora 7, and
154 may be fixed in the final Fedora 7 release. To stop the crash from
155 happening, first try upgrading to the newest version of glibc; if this
156 does not work, rebuild Emacs with the same version of glibc that you
157 will run it under. For details, see
159 https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=239344
163 ** Emacs crashes when running in a terminal, if compiled with GCC 4.5.0
164 This version of GCC is buggy: see
166 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=6031
167 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43904
169 You can work around this error in gcc-4.5 by omitting sibling call
170 optimization. To do this, configure Emacs with
172 CFLAGS="-g -O2 -fno-optimize-sibling-calls" ./configure
174 ** Emacs compiled with GCC 4.6.1 crashes on MS-Windows when C-g is pressed
176 This is known to happen when Emacs is compiled with MinGW GCC 4.6.1
177 with the -O2 option (which is the default in the Windows build). The
178 reason is a bug in MinGW GCC 4.6.1; to work around, either add the
179 `-fno-omit-frame-pointer' switch to GCC or compile without
180 optimizations (`--no-opt' switch to the configure.bat script).
182 ** Emacs crashes in x-popup-dialog.
184 This can happen if the dialog widget cannot find the font it wants to
185 use. You can work around the problem by specifying another font with
186 an X resource--for example, `Emacs.dialog*.font: 9x15' (or any font that
187 happens to exist on your X server).
189 ** Emacs crashes when you use Bibtex mode.
191 This happens if your system puts a small limit on stack size. You can
192 prevent the problem by using a suitable shell command (often `ulimit')
193 to raise the stack size limit before you run Emacs.
195 Patches to raise the stack size limit automatically in `main'
196 (src/emacs.c) on various systems would be greatly appreciated.
198 ** Error message `Symbol's value as variable is void: x', followed by
199 a segmentation fault and core dump.
201 This has been tracked to a bug in tar! People report that tar erroneously
202 added a line like this at the beginning of files of Lisp code:
204 x FILENAME, N bytes, B tape blocks
206 If your tar has this problem, install GNU tar--if you can manage to
209 ** Crashes when displaying GIF images in Emacs built with version
210 libungif-4.1.0 are resolved by using version libungif-4.1.0b1.
211 Configure checks for the correct version, but this problem could occur
212 if a binary built against a shared libungif is run on a system with an
215 ** Emacs aborts inside the function `tparam1'.
217 This can happen if Emacs was built without terminfo support, but the
218 terminal's capabilities use format that is only supported by terminfo.
219 If your system has ncurses installed, this might happen if your
220 version of ncurses is broken; upgrading to a newer version of ncurses
221 and reconfiguring and rebuilding Emacs should solve this.
223 All modern systems support terminfo, so even if ncurses is not the
224 problem, you should look for a way to configure Emacs so that it uses
227 ** Emacs crashes when using some version of the Exceed X server.
229 Upgrading to a newer version of Exceed has been reported to prevent
230 these crashes. You should consider switching to a free X server, such
231 as Xming or Cygwin/X.
233 ** Emacs crashes with SIGSEGV in XtInitializeWidgetClass.
235 It crashes on X, but runs fine when called with option "-nw".
237 This has been observed when Emacs is linked with GNU ld but without passing
238 the -z nocombreloc flag. Emacs normally knows to pass the -z nocombreloc
239 flag when needed, so if you come across a situation where the flag is
240 necessary but missing, please report it via M-x report-emacs-bug.
242 On platforms such as Solaris, you can also work around this problem by
243 configuring your compiler to use the native linker instead of GNU ld.
245 ** When Emacs is compiled with Gtk+, closing a display kills Emacs.
247 There is a long-standing bug in GTK that prevents it from recovering
248 from disconnects: http://bugzilla.gnome.org/show_bug.cgi?id=85715.
250 Thus, for instance, when Emacs is run as a server on a text terminal,
251 and an X frame is created, and the X server for that frame crashes or
252 exits unexpectedly, Emacs must exit to prevent a GTK error that would
253 result in an endless loop.
255 If you need Emacs to be able to recover from closing displays, compile
256 it with the Lucid toolkit instead of GTK.
258 * General runtime problems
262 *** Changes made to .el files do not take effect.
264 You may have forgotten to recompile them into .elc files.
265 Then the old .elc files will be loaded, and your changes
266 will not be seen. To fix this, do M-x byte-recompile-directory
267 and specify the directory that contains the Lisp files.
269 Emacs should print a warning when loading a .elc file which is older
270 than the corresponding .el file.
272 *** Watch out for .emacs files and EMACSLOADPATH environment vars.
274 These control the actions of Emacs.
275 ~/.emacs is your Emacs init file.
276 EMACSLOADPATH overrides which directories the function "load" will search.
278 If you observe strange problems, check for these and get rid
279 of them, then try again.
281 *** Using epop3.el package causes Emacs to signal an error.
283 The error message might be something like this:
285 "Lisp nesting exceeds max-lisp-eval-depth"
287 This happens because epop3 redefines the function gethash, which is a
288 built-in primitive beginning with Emacs 21.1. We don't have a patch
289 for epop3 that fixes this, but perhaps a newer version of epop3
292 *** Buffers from `with-output-to-temp-buffer' get set up in Help mode.
294 Changes in Emacs 20.4 to the hooks used by that function cause
295 problems for some packages, specifically BBDB. See the function's
296 documentation for the hooks involved. BBDB 2.00.06 fixes the problem.
298 *** The Hyperbole package causes *Help* buffers not to be displayed in
299 Help mode due to setting `temp-buffer-show-hook' rather than using
300 `add-hook'. Using `(add-hook 'temp-buffer-show-hook
301 'help-mode-maybe)' after loading Hyperbole should fix this.
305 *** Unable to enter the M-| key on some German keyboards.
306 Some users have reported that M-| suffers from "keyboard ghosting".
307 This can't be fixed by Emacs, as the keypress never gets passed to it
308 at all (as can be verified using "xev"). You can work around this by
309 typing `ESC |' instead.
311 *** "Compose Character" key does strange things when used as a Meta key.
313 If you define one key to serve as both Meta and Compose Character, you
314 will get strange results. In previous Emacs versions, this "worked"
315 in that the key acted as Meta--that's because the older Emacs versions
316 did not try to support Compose Character. Now Emacs tries to do
317 character composition in the standard X way. This means that you
318 must pick one meaning or the other for any given key.
320 You can use both functions (Meta, and Compose Character) if you assign
321 them to two different keys.
323 *** C-z just refreshes the screen instead of suspending Emacs.
325 You are probably using a shell that doesn't support job control, even
326 though the system itself is capable of it. Either use a different shell,
327 or set the variable `cannot-suspend' to a non-nil value.
329 *** With M-x enable-flow-control, you need to type C-\ twice
330 to do incremental search--a single C-\ gets no response.
332 This has been traced to communicating with your machine via kermit,
333 with C-\ as the kermit escape character. One solution is to use
334 another escape character in kermit. One user did
336 set escape-character 17
338 in his .kermrc file, to make C-q the kermit escape character.
340 ** Mailers and other helper programs
342 *** movemail compiled with POP support can't connect to the POP server.
344 Make sure that the `pop' entry in /etc/services, or in the services
345 NIS map if your machine uses NIS, has the same port number as the
346 entry on the POP server. A common error is for the POP server to be
347 listening on port 110, the assigned port for the POP3 protocol, while
348 the client is trying to connect on port 109, the assigned port for the
351 *** RMAIL gets error getting new mail.
353 RMAIL gets new mail from /usr/spool/mail/$USER using a program
354 called `movemail'. This program interlocks with /bin/mail using
355 the protocol defined by /bin/mail.
357 There are two different protocols in general use. One of them uses
358 the `flock' system call. The other involves creating a lock file;
359 `movemail' must be able to write in /usr/spool/mail in order to do
360 this. You control which one is used by defining, or not defining,
361 the macro MAIL_USE_FLOCK in config.h or the m/ or s/ file it includes.
362 IF YOU DON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOUR
363 SYSTEM, YOU CAN LOSE MAIL!
365 If your system uses the lock file protocol, and fascist restrictions
366 prevent ordinary users from writing the lock files in /usr/spool/mail,
367 you may need to make `movemail' setgid to a suitable group such as
368 `mail'. To do this, use the following commands (as root) after doing the
374 Installation normally copies movemail from the build directory to an
375 installation directory which is usually under /usr/local/lib. The
376 installed copy of movemail is usually in the directory
377 /usr/local/lib/emacs/VERSION/TARGET. You must change the group and
378 mode of the installed copy; changing the group and mode of the build
379 directory copy is ineffective.
381 *** rcs2log gives you the awk error message "too many fields".
383 This is due to an arbitrary limit in certain versions of awk.
384 The solution is to use gawk (GNU awk).
386 ** Problems with hostname resolution
388 *** Emacs fails to understand most Internet host names, even though
389 the names work properly with other programs on the same system.
390 *** Emacs won't work with X-windows if the value of DISPLAY is HOSTNAME:0.
391 *** Gnus can't make contact with the specified host for nntp.
393 This typically happens on Suns and other systems that use shared
394 libraries. The cause is that the site has installed a version of the
395 shared library which uses a name server--but has not installed a
396 similar version of the unshared library which Emacs uses.
398 The result is that most programs, using the shared library, work with
399 the nameserver, but Emacs does not.
401 The fix is to install an unshared library that corresponds to what you
402 installed in the shared library, and then relink Emacs.
404 If you have already installed the name resolver in the file libresolv.a,
405 then you need to compile Emacs to use that library. The easiest way to
406 do this is to add to config.h a definition of LIBS_SYSTEM, LIBS_MACHINE
407 or LIB_STANDARD which uses -lresolv. Watch out! If you redefine a macro
408 that is already in use in your configuration to supply some other libraries,
409 be careful not to lose the others.
411 Thus, you could start by adding this to config.h:
413 #define LIBS_SYSTEM -lresolv
415 Then if this gives you an error for redefining a macro, and you see that
416 the s- file defines LIBS_SYSTEM as -lfoo -lbar, you could change config.h
419 #define LIBS_SYSTEM -lresolv -lfoo -lbar
421 *** Emacs does not know your host's fully-qualified domain name.
423 For example, (system-name) returns some variation on
424 "localhost.localdomain", rather the name you were expecting.
426 You need to configure your machine with a fully qualified domain name,
427 (i.e. a name with at least one ".") either in /etc/hosts,
428 /etc/hostname, the NIS, or wherever your system calls for specifying this.
430 If you cannot fix the configuration, you can set the Lisp variable
431 mail-host-address to the value you want.
435 *** Emacs says it has saved a file, but the file does not actually
438 This can happen on certain systems when you are using NFS, if the
439 remote disk is full. It is due to a bug in NFS (or certain NFS
440 implementations), and there is apparently nothing Emacs can do to
441 detect the problem. Emacs checks the failure codes of all the system
442 calls involved in writing a file, including `close'; but in the case
443 where the problem occurs, none of those system calls fails.
445 *** Editing files through RFS gives spurious "file has changed" warnings.
446 It is possible that a change in Emacs 18.37 gets around this problem,
447 but in case not, here is a description of how to fix the RFS bug that
450 There was a serious pair of bugs in the handling of the fsync() system
451 call in the RFS server.
453 The first is that the fsync() call is handled as another name for the
454 close() system call (!!). It appears that fsync() is not used by very
455 many programs; Emacs version 18 does an fsync() before closing files
456 to make sure that the bits are on the disk.
458 This is fixed by the enclosed patch to the RFS server.
460 The second, more serious problem, is that fsync() is treated as a
461 non-blocking system call (i.e., it's implemented as a message that
462 gets sent to the remote system without waiting for a reply). Fsync is
463 a useful tool for building atomic file transactions. Implementing it
464 as a non-blocking RPC call (when the local call blocks until the sync
465 is done) is a bad idea; unfortunately, changing it will break the RFS
466 protocol. No fix was supplied for this problem.
468 (as always, your line numbers may vary)
470 % rcsdiff -c -r1.2 serversyscall.c
471 RCS file: RCS/serversyscall.c,v
472 retrieving revision 1.2
473 diff -c -r1.2 serversyscall.c
474 *** /tmp/,RCSt1003677 Wed Jan 28 15:15:02 1987
475 --- serversyscall.c Wed Jan 28 15:14:48 1987
479 * No return sent for close or fsync!
481 ! if (syscall == RSYS_close || syscall == RSYS_fsync)
482 proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
487 * No return sent for close or fsync!
489 ! if (syscall == RSYS_close)
490 proc->p_returnval = deallocate_fd(proc, msg->m_args[0]);
494 ** PSGML conflicts with sgml-mode.
496 PSGML package uses the same names of some variables (like keymap)
497 as built-in sgml-mode.el because it was created as a replacement
498 of that package. The conflict will be shown if you load
499 sgml-mode.el before psgml.el. E.g. this could happen if you edit
500 HTML page and then start to work with SGML or XML file. html-mode
501 (from sgml-mode.el) is used for HTML file and loading of psgml.el
502 (for sgml-mode or xml-mode) will cause an error.
506 *** Lines are not updated or new lines are added in the buffer upon commit.
508 When committing files located higher in the hierarchy than the examined
509 directory, some versions of the CVS program return an ambiguous message
510 from which PCL-CVS cannot extract the full location of the committed
511 files. As a result, the corresponding lines in the PCL-CVS buffer are
512 not updated with the new revision of these files, and new lines are
513 added to the top-level directory.
515 This can happen with CVS versions 1.12.8 and 1.12.9. Upgrade to CVS
516 1.12.10 or newer to fix this problem.
518 ** Miscellaneous problems
520 *** Editing files with very long lines is slow.
522 For example, simply moving through a file that contains hundreds of
523 thousands of characters per line is slow, and consumes a lot of CPU.
524 This is a known limitation of Emacs with no solution at this time.
526 *** Emacs uses 100% of CPU time
528 This is a known problem with some versions of the Semantic package.
529 The solution is to upgrade Semantic to version 2.0pre4 (distributed
530 with CEDET 1.0pre4) or later.
532 *** Self-documentation messages are garbled.
534 This means that the file `etc/DOC-...' doesn't properly correspond
535 with the Emacs executable. Redumping Emacs and then installing the
536 corresponding pair of files should fix the problem.
538 *** Programs running under terminal emulator do not recognize `emacs'
541 The cause of this is a shell startup file that sets the TERMCAP
542 environment variable. The terminal emulator uses that variable to
543 provide the information on the special terminal type that Emacs emulates.
545 Rewrite your shell startup file so that it does not change TERMCAP
546 in such a case. You could use the following conditional which sets
547 it only if it is undefined.
549 if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-file
551 Or you could set TERMCAP only when you set TERM--which should not
552 happen in a non-login shell.
554 *** In Shell mode, you get a ^M at the end of every line.
556 This happens to people who use tcsh, because it is trying to be too
557 smart. It sees that the Shell uses terminal type `unknown' and turns
558 on the flag to output ^M at the end of each line. You can fix the
559 problem by adding this to your .cshrc file:
562 if ("$EMACS" =~ /*) then
564 stty -icrnl -onlcr -echo susp ^Z
568 *** Emacs startup on GNU/Linux systems (and possibly other systems) is slow.
570 This can happen if the system is misconfigured and Emacs can't get the
571 full qualified domain name, FQDN. You should have your FQDN in the
572 /etc/hosts file, something like this:
575 129.187.137.82 nuc04.t30.physik.tu-muenchen.de nuc04
577 The way to set this up may vary on non-GNU systems.
579 *** Attempting to visit remote files via ange-ftp fails.
581 If the error message is "ange-ftp-file-modtime: Specified time is not
582 representable", then this could happen when `lukemftp' is used as the
583 ftp client. This was reported to happen on Debian GNU/Linux, kernel
584 version 2.4.3, with `lukemftp' 1.5-5, but might happen on other
585 systems as well. To avoid this problem, switch to using the standard
586 ftp client. On a Debian system, type
588 update-alternatives --config ftp
590 and then choose /usr/bin/netkit-ftp.
592 *** JPEG images aren't displayed.
594 This has been reported when Emacs is built with jpeg-6a library.
595 Upgrading to jpeg-6b solves the problem. Configure checks for the
596 correct version, but this problem could occur if a binary built
597 against a shared libjpeg is run on a system with an older version.
599 *** Dired is very slow.
601 This could happen if invocation of the `df' program takes a long
602 time. Possible reasons for this include:
604 - ClearCase mounted filesystems (VOBs) that sometimes make `df'
605 response time extremely slow (dozens of seconds);
607 - slow automounters on some old versions of Unix;
609 - slow operation of some versions of `df'.
611 To work around the problem, you could either (a) set the variable
612 `directory-free-space-program' to nil, and thus prevent Emacs from
613 invoking `df'; (b) use `df' from the GNU Fileutils package; or
614 (c) use CVS, which is Free Software, instead of ClearCase.
616 *** ps-print commands fail to find prologue files ps-prin*.ps.
618 This can happen if you use an old version of X-Symbol package: it
619 defines compatibility functions which trick ps-print into thinking it
620 runs in XEmacs, and look for the prologue files in a wrong directory.
622 The solution is to upgrade X-Symbol to a later version.
624 *** On systems with shared libraries you might encounter run-time errors
625 from the dynamic linker telling you that it is unable to find some
626 shared libraries, for instance those for Xaw3d or image support.
627 These errors mean Emacs has been linked with a library whose shared
628 library is not in the default search path of the dynamic linker.
630 Similar problems could prevent Emacs from building, since the build
631 process invokes Emacs several times.
633 On many systems, it is possible to set LD_LIBRARY_PATH in your
634 environment to specify additional directories where shared libraries
637 Other systems allow to set LD_RUN_PATH in a similar way, but before
638 Emacs is linked. With LD_RUN_PATH set, the linker will include a
639 specified run-time search path in the executable.
641 On some systems, Emacs can crash due to problems with dynamic
642 linking. Specifically, on SGI Irix 6.5, crashes were reported with
643 backtraces like this:
646 0 strcmp(0xf49239d, 0x4031184, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2) ["/xlv22/ficus-jan23/work/irix/lib/libc/libc_n32_M3_ns/strings/strcmp.s":35, 0xfb7e480]
647 1 general_find_symbol(0xf49239d, 0x0, 0x0, 0x0, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
648 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":2140, 0xfb65a98]
649 2 resolve_symbol(0xf49239d, 0x4031184, 0x0, 0xfbdd438, 0x0, 0xf4923aa, 0x0, 0x492ddb2)
650 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":1947, 0xfb657e4]
651 3 lazy_text_resolve(0xd18, 0x1a3, 0x40302b4, 0x12, 0xf0000000, 0xf4923aa, 0x0, 0x492ddb2)
652 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld.c":997, 0xfb64d44]
653 4 _rld_text_resolve(0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0)
654 ["/comp2/mtibuild/v73/workarea/v7.3/rld/rld_bridge.s":175, 0xfb6032c]
656 (`rld' is the dynamic linker.) We don't know yet why this
657 happens, but setting the environment variable LD_BIND_NOW to 1 (which
658 forces the dynamic linker to bind all shared objects early on) seems
659 to work around the problem.
661 Please refer to the documentation of your dynamic linker for details.
663 *** You request inverse video, and the first Emacs frame is in inverse
664 video, but later frames are not in inverse video.
666 This can happen if you have an old version of the custom library in
667 your search path for Lisp packages. Use M-x list-load-path-shadows to
668 check whether this is true. If it is, delete the old custom library.
670 *** When you run Ispell from Emacs, it reports a "misalignment" error.
672 This can happen if you compiled the Ispell program to use ASCII
673 characters only and then try to use it from Emacs with non-ASCII
674 characters, like Latin-1. The solution is to recompile Ispell with
675 support for 8-bit characters.
677 To see whether your Ispell program supports 8-bit characters, type
678 this at your shell's prompt:
682 and look in the output for the string "NO8BIT". If Ispell says
683 "!NO8BIT (8BIT)", your speller supports 8-bit characters; otherwise it
686 To rebuild Ispell with 8-bit character support, edit the local.h file
687 in the Ispell distribution and make sure it does _not_ define NO8BIT.
688 Then rebuild the speller.
690 Another possible cause for "misalignment" error messages is that the
691 version of Ispell installed on your machine is old. Upgrade.
693 Yet another possibility is that you are trying to spell-check a word
694 in a language that doesn't fit the dictionary you choose for use by
695 Ispell. (Ispell can only spell-check one language at a time, because
696 it uses a single dictionary.) Make sure that the text you are
697 spelling and the dictionary used by Ispell conform to each other.
699 If your spell-checking program is Aspell, it has been reported that if
700 you have a personal configuration file (normally ~/.aspell.conf), it
701 can cause this error. Remove that file, execute `ispell-kill-ispell'
702 in Emacs, and then try spell-checking again.
704 * Runtime problems related to font handling
706 ** Characters are displayed as empty boxes or with wrong font under X.
708 *** This can occur when two different versions of FontConfig are used.
709 For example, XFree86 4.3.0 has one version and Gnome usually comes
710 with a newer version. Emacs compiled with Gtk+ will then use the
711 newer version. In most cases the problem can be temporarily fixed by
712 stopping the application that has the error (it can be Emacs or any
713 other application), removing ~/.fonts.cache-1, and then start the
714 application again. If removing ~/.fonts.cache-1 and restarting
715 doesn't help, the application with problem must be recompiled with the
716 same version of FontConfig as the rest of the system uses. For KDE,
717 it is sufficient to recompile Qt.
719 *** Some fonts have a missing glyph and no default character. This is
720 known to occur for character number 160 (no-break space) in some
721 fonts, such as Lucida but Emacs sets the display table for the unibyte
722 and Latin-1 version of this character to display a space.
724 *** Some of the fonts called for in your fontset may not exist on your
727 Each X11 font covers just a fraction of the characters that Emacs
728 supports. To display the whole range of Emacs characters requires
729 many different fonts, collected into a fontset. You can remedy the
730 problem by installing additional fonts.
732 The intlfonts distribution includes a full spectrum of fonts that can
733 display all the characters Emacs supports. The etl-unicode collection
734 of fonts (available from <URL:ftp://ftp.x.org/contrib/fonts/> and
735 <URL:ftp://ftp.xfree86.org/pub/mirror/X.Org/contrib/fonts/>) includes
736 fonts that can display many Unicode characters; they can also be used
737 by ps-print and ps-mule to print Unicode characters.
739 ** Under X11, some characters appear improperly aligned in their lines.
741 You may have bad X11 fonts; try installing the intlfonts distribution
742 or the etl-unicode collection (see above).
744 ** Under X, an unexpected monospace font is used as the default font.
746 When compiled with XFT, Emacs tries to use a default font named
747 "monospace". This is a "virtual font", which the operating system
748 (Fontconfig) redirects to a suitable font such as DejaVu Sans Mono.
749 On some systems, there exists a font that is actually named Monospace,
750 which takes over the virtual font. This is considered an operating
753 http://lists.gnu.org/archive/html/emacs-devel/2008-10/msg00696.html
755 If you encounter this problem, set the default font to a specific font
756 in your .Xresources or initialization file. For instance, you can put
757 the following in your .Xresources:
759 Emacs.font: DejaVu Sans Mono 12
761 ** Certain fonts make each line take one pixel more than it should.
763 This is because these fonts contain characters a little taller than
764 the font's nominal height. Emacs needs to make sure that lines do not
767 ** Loading fonts is very slow.
769 You might be getting scalable fonts instead of precomputed bitmaps.
770 Known scalable font directories are "Type1" and "Speedo". A font
771 directory contains scalable fonts if it contains the file
774 If this is so, re-order your X windows font path to put the scalable
775 font directories last. See the documentation of `xset' for details.
777 With some X servers, it may be necessary to take the scalable font
778 directories out of your path entirely, at least for Emacs 19.26.
779 Changes in the future may make this unnecessary.
781 ** Font Lock displays portions of the buffer in incorrect faces.
783 By far the most frequent cause of this is a parenthesis `(' or a brace
784 `{' in column zero. Font Lock assumes that such a paren is outside of
785 any comment or string. This is of course not true in general, but the
786 vast majority of well-formatted program source files don't have such
787 parens, and therefore this assumption is used to allow optimizations
788 in Font Lock's syntactical analysis. These optimizations avoid some
789 pathological cases where jit-lock, the Just-in-Time fontification
790 introduced with Emacs 21.1, could significantly slow down scrolling
791 through the buffer, especially scrolling backwards, and also jumping
792 to the end of a very large buffer.
794 Beginning with version 22.1, a parenthesis or a brace in column zero
795 is highlighted in bold-red face if it is inside a string or a comment,
796 to indicate that it could interfere with Font Lock (and also with
797 indentation) and should be moved or escaped with a backslash.
799 If you don't use large buffers, or have a very fast machine which
800 makes the delays insignificant, you can avoid the incorrect
801 fontification by setting the variable
802 `font-lock-beginning-of-syntax-function' to a nil value. (This must
803 be done _after_ turning on Font Lock.)
805 Another alternative is to avoid a paren in column zero. For example,
806 in a Lisp string you could precede the paren with a backslash.
808 ** With certain fonts, when the cursor appears on a character, the
809 character doesn't appear--you get a solid box instead.
811 One user on a Linux-based GNU system reported that this problem went
812 away with installation of a new X server. The failing server was
813 XFree86 3.1.1. XFree86 3.1.2 works.
815 ** Emacs pauses for several seconds when changing the default font.
817 This has been reported for fvwm 2.2.5 and the window manager of KDE
818 2.1. The reason for the pause is Xt waiting for a ConfigureNotify
819 event from the window manager, which the window manager doesn't send.
820 Xt stops waiting after a default timeout of usually 5 seconds.
822 A workaround for this is to add something like
824 emacs.waitForWM: false
826 to your X resources. Alternatively, add `(wait-for-wm . nil)' to a
827 frame's parameter list, like this:
829 (modify-frame-parameters nil '((wait-for-wm . nil)))
831 (this should go into your `.emacs' file).
833 ** Underlines appear at the wrong position.
835 This is caused by fonts having a wrong UNDERLINE_POSITION property.
836 Examples are the font 7x13 on XFree prior to version 4.1, or the jmk
837 neep font from the Debian xfonts-jmk package prior to version 3.0.17.
838 To circumvent this problem, set x-use-underline-position-properties
839 to nil in your `.emacs'.
841 To see what is the value of UNDERLINE_POSITION defined by the font,
842 type `xlsfonts -lll FONT' and look at the font's UNDERLINE_POSITION property.
844 ** When using Exceed, fonts sometimes appear too tall.
846 When the display is set to an Exceed X-server and fonts are specified
847 (either explicitly with the -fn option or implicitly with X resources)
848 then the fonts may appear "too tall". The actual character sizes are
849 correct but there is too much vertical spacing between rows, which
850 gives the appearance of "double spacing".
852 To prevent this, turn off the Exceed's "automatic font substitution"
853 feature (in the font part of the configuration window).
855 ** Subscript/superscript text in TeX is hard to read.
857 If `tex-fontify-script' is non-nil, tex-mode displays
858 subscript/superscript text in the faces subscript/superscript, which
859 are smaller than the normal font and lowered/raised. With some fonts,
860 nested superscripts (say) can be hard to read. Switching to a
861 different font, or changing your antialiasing setting (on an LCD
862 screen), can both make the problem disappear. Alternatively, customize
863 the following variables: tex-font-script-display (how much to
864 lower/raise); tex-suscript-height-ratio (how much smaller than
865 normal); tex-suscript-height-minimum (minimum height).
867 * Internationalization problems
869 ** M-{ does not work on a Spanish PC keyboard.
871 Many Spanish keyboards seem to ignore that combination. Emacs can't
872 do anything about it.
874 ** International characters aren't displayed under X.
878 XFree86 4 contains many fonts in iso10646-1 encoding which have
879 minimal character repertoires (whereas the encoding part of the font
880 name is meant to be a reasonable indication of the repertoire
881 according to the XLFD spec). Emacs may choose one of these to display
882 characters from the mule-unicode charsets and then typically won't be
883 able to find the glyphs to display many characters. (Check with C-u
884 C-x = .) To avoid this, you may need to use a fontset which sets the
885 font for the mule-unicode sets explicitly. E.g. to use GNU unifont,
886 include in the fontset spec:
888 mule-unicode-2500-33ff:-gnu-unifont-*-iso10646-1,\
889 mule-unicode-e000-ffff:-gnu-unifont-*-iso10646-1,\
890 mule-unicode-0100-24ff:-gnu-unifont-*-iso10646-1
892 ** The UTF-8/16/7 coding systems don't encode CJK (Far Eastern) characters.
894 Emacs directly supports the Unicode BMP whose code points are in the
895 ranges 0000-33ff and e000-ffff, and indirectly supports the parts of
896 CJK characters belonging to these legacy charsets:
898 GB2312, Big5, JISX0208, JISX0212, JISX0213-1, JISX0213-2, KSC5601
900 The latter support is done in Utf-Translate-Cjk mode (turned on by
901 default). Which Unicode CJK characters are decoded into which Emacs
902 charset is decided by the current language environment. For instance,
903 in Chinese-GB, most of them are decoded into chinese-gb2312.
905 If you read UTF-8 data with code points outside these ranges, the
906 characters appear in the buffer as raw bytes of the original UTF-8
907 (composed into a single quasi-character) and they will be written back
908 correctly as UTF-8, assuming you don't break the composed sequences.
909 If you read such characters from UTF-16 or UTF-7 data, they are
910 substituted with the Unicode `replacement character', and you lose
913 ** Accented ISO-8859-1 characters are displayed as | or _.
915 Try other font set sizes (S-mouse-1). If the problem persists with
916 other sizes as well, your text is corrupted, probably through software
917 that is not 8-bit clean. If the problem goes away with another font
918 size, it's probably because some fonts pretend to be ISO-8859-1 fonts
919 when they are really ASCII fonts. In particular the schumacher-clean
920 fonts have this bug in some versions of X.
922 To see what glyphs are included in a font, use `xfd', like this:
924 xfd -fn -schumacher-clean-medium-r-normal--12-120-75-75-c-60-iso8859-1
926 If this shows only ASCII glyphs, the font is indeed the source of the problem.
928 The solution is to remove the corresponding lines from the appropriate
929 `fonts.alias' file, then run `mkfontdir' in that directory, and then run
932 ** The `oc-unicode' package doesn't work with Emacs 21.
934 This package tries to define more private charsets than there are free
935 slots now. The current built-in Unicode support is actually more
936 flexible. (Use option `utf-translate-cjk-mode' if you need CJK
937 support.) Files encoded as emacs-mule using oc-unicode aren't
938 generally read correctly by Emacs 21.
940 ** After a while, Emacs slips into unibyte mode.
942 The VM mail package, which is not part of Emacs, sometimes does
943 (standard-display-european t)
944 That should be changed to
945 (standard-display-european 1 t)
949 ** X keyboard problems
951 *** You "lose characters" after typing Compose Character key.
953 This is because the Compose Character key is defined as the keysym
954 Multi_key, and Emacs (seeing that) does the proper X11
955 character-composition processing. If you don't want your Compose key
956 to do that, you can redefine it with xmodmap.
958 For example, here's one way to turn it into a Meta key:
960 xmodmap -e "keysym Multi_key = Meta_L"
962 If all users at your site of a particular keyboard prefer Meta to
963 Compose, you can make the remapping happen automatically by adding the
964 xmodmap command to the xdm setup script for that display.
966 *** Using X Windows, control-shift-leftbutton makes Emacs hang.
968 Use the shell command `xset bc' to make the old X Menu package work.
970 *** C-SPC fails to work on Fedora GNU/Linux (or with fcitx input method).
972 Fedora Core 4 steals the C-SPC key by default for the `iiimx' program
973 which is the input method for some languages. It blocks Emacs users
974 from using the C-SPC key for `set-mark-command'.
976 One solutions is to remove the `<Ctrl>space' from the `Iiimx' file
977 which can be found in the `/usr/lib/X11/app-defaults' directory.
978 However, that requires root access.
980 Another is to specify `Emacs*useXIM: false' in your X resources.
982 Another is to build Emacs with the `--without-xim' configure option.
984 The same problem happens on any other system if you are using fcitx
985 (Chinese input method) which by default use C-SPC for toggling. If
986 you want to use fcitx with Emacs, you have two choices. Toggle fcitx
987 by another key (e.g. C-\) by modifying ~/.fcitx/config, or be
988 accustomed to use C-@ for `set-mark-command'.
990 *** M-SPC seems to be ignored as input.
992 See if your X server is set up to use this as a command
993 for character composition.
995 *** The S-C-t key combination doesn't get passed to Emacs on X.
997 This happens because some X configurations assign the Ctrl-Shift-t
998 combination the same meaning as the Multi_key. The offending
999 definition is in the file `...lib/X11/locale/iso8859-1/Compose'; there
1000 might be other similar combinations which are grabbed by X for similar
1003 We think that this can be countermanded with the `xmodmap' utility, if
1004 you want to be able to bind one of these key sequences within Emacs.
1006 *** Under X, C-v and/or other keys don't work.
1008 These may have been intercepted by your window manager. In
1009 particular, AfterStep 1.6 is reported to steal C-v in its default
1010 configuration. Various Meta keys are also likely to be taken by the
1011 configuration of the `feel'. See the WM's documentation for how to
1014 *** Clicking C-mouse-2 in the scroll bar doesn't split the window.
1016 This currently doesn't work with scroll-bar widgets (and we don't know
1017 a good way of implementing it with widgets). If Emacs is configured
1018 --without-toolkit-scroll-bars, C-mouse-2 on the scroll bar does work.
1020 *** Inability to send an Alt-modified key, when Emacs is communicating
1021 directly with an X server.
1023 If you have tried to bind an Alt-modified key as a command, and it
1024 does not work to type the command, the first thing you should check is
1025 whether the key is getting through to Emacs. To do this, type C-h c
1026 followed by the Alt-modified key. C-h c should say what kind of event
1027 it read. If it says it read an Alt-modified key, then make sure you
1028 have made the key binding correctly.
1030 If C-h c reports an event that doesn't have the Alt modifier, it may
1031 be because your X server has no key for the Alt modifier. The X
1032 server that comes from MIT does not set up the Alt modifier by default.
1034 If your keyboard has keys named Alt, you can enable them as follows:
1036 xmodmap -e 'add mod2 = Alt_L'
1037 xmodmap -e 'add mod2 = Alt_R'
1039 If the keyboard has just one key named Alt, then only one of those
1040 commands is needed. The modifier `mod2' is a reasonable choice if you
1041 are using an unmodified MIT version of X. Otherwise, choose any
1042 modifier bit not otherwise used.
1044 If your keyboard does not have keys named Alt, you can use some other
1045 keys. Use the keysym command in xmodmap to turn a function key (or
1046 some other 'spare' key) into Alt_L or into Alt_R, and then use the
1047 commands show above to make them modifier keys.
1049 Note that if you have Alt keys but no Meta keys, Emacs translates Alt
1050 into Meta. This is because of the great importance of Meta in Emacs.
1052 ** Window-manager and toolkit-related problems
1054 *** Metacity: Resizing Emacs or ALT-Tab causes X to be unresponsive.
1056 This happens sometimes when using Metacity. Resizing Emacs or ALT-Tab:bing
1057 makes the system unresponsive to the mouse or the keyboard. Killing Emacs
1058 or shifting out from X11 and back again usually cures it (i.e. Ctrl-Alt-F1
1059 and then Alt-F7). A bug for it is here:
1060 https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/231034.
1061 Note that a permanent fix seems to be to disable "assistive technologies".
1063 *** Gnome: Emacs receives input directly from the keyboard, bypassing XIM.
1065 This seems to happen when gnome-settings-daemon version 2.12 or later
1066 is running. If gnome-settings-daemon is not running, Emacs receives
1067 input through XIM without any problem. Furthermore, this seems only
1068 to happen in *.UTF-8 locales; zh_CN.GB2312 and zh_CN.GBK locales, for
1069 example, work fine. A bug report has been filed in the Gnome
1070 bugzilla: http://bugzilla.gnome.org/show_bug.cgi?id=357032
1072 *** Gnome: Emacs' xterm-mouse-mode doesn't work on the Gnome terminal.
1074 A symptom of this bug is that double-clicks insert a control sequence
1075 into the buffer. The reason this happens is an apparent
1076 incompatibility of the Gnome terminal with Xterm, which also affects
1077 other programs using the Xterm mouse interface. A problem report has
1080 *** KDE: When running on KDE, colors or fonts are not as specified for Emacs,
1083 For example, you could see background you set for Emacs only in the
1084 empty portions of the Emacs display, while characters have some other
1087 This happens because KDE's defaults apply its color and font
1088 definitions even to applications that weren't compiled for KDE. The
1089 solution is to uncheck the "Apply fonts and colors to non-KDE apps"
1090 option in Preferences->Look&Feel->Style (KDE 2). In KDE 3, this option
1091 is in the "Colors" section, rather than "Style".
1093 Alternatively, if you do want the KDE defaults to apply to other
1094 applications, but not to Emacs, you could modify the file `Emacs.ad'
1095 (should be in the `/usr/share/apps/kdisplay/app-defaults/' directory)
1096 so that it doesn't set the default background and foreground only for
1097 Emacs. For example, make sure the following resources are either not
1098 present or commented out:
1100 Emacs.default.attributeForeground
1101 Emacs.default.attributeBackground
1105 It is also reported that a bug in the gtk-engines-qt engine can cause this if
1106 Emacs is compiled with Gtk+.
1107 The bug is fixed in version 0.7 or newer of gtk-engines-qt.
1109 *** KDE: Emacs hangs on KDE when a large portion of text is killed.
1111 This is caused by a bug in the KDE applet `klipper' which periodically
1112 requests the X clipboard contents from applications. Early versions
1113 of klipper don't implement the ICCCM protocol for large selections,
1114 which leads to Emacs being flooded with selection requests. After a
1115 while, Emacs may print a message:
1117 Timed out waiting for property-notify event
1119 A workaround is to not use `klipper'. An upgrade to the `klipper' that
1120 comes with KDE 3.3 or later also solves the problem.
1122 *** CDE: Frames may cover dialogs they created when using CDE.
1124 This can happen if you have "Allow Primary Windows On Top" enabled which
1125 seems to be the default in the Common Desktop Environment.
1126 To change, go in to "Desktop Controls" -> "Window Style Manager"
1127 and uncheck "Allow Primary Windows On Top".
1129 *** Xaw3d : When using Xaw3d scroll bars without arrows, the very first mouse
1130 click in a scroll bar might be ignored by the scroll bar widget. This
1131 is probably a bug in Xaw3d; when Xaw3d is compiled with arrows, the
1134 *** Xaw: There are known binary incompatibilities between Xaw, Xaw3d, neXtaw,
1135 XawM and the few other derivatives of Xaw. So when you compile with
1136 one of these, it may not work to dynamically link with another one.
1137 For example, strange problems, such as Emacs exiting when you type
1138 "C-x 1", were reported when Emacs compiled with Xaw3d and libXaw was
1139 used with neXtaw at run time.
1141 The solution is to rebuild Emacs with the toolkit version you actually
1142 want to use, or set LD_PRELOAD to preload the same toolkit version you
1145 *** Open Motif: Problems with file dialogs in Emacs built with Open Motif.
1147 When Emacs 21 is built with Open Motif 2.1, it can happen that the
1148 graphical file dialog boxes do not work properly. The "OK", "Filter"
1149 and "Cancel" buttons do not respond to mouse clicks. Dragging the
1150 file dialog window usually causes the buttons to work again.
1152 The solution is to use LessTif instead. LessTif is a free replacement
1153 for Motif. See the file INSTALL for information on how to do this.
1155 Another workaround is not to use the mouse to trigger file prompts,
1156 but to use the keyboard. This way, you will be prompted for a file in
1157 the minibuffer instead of a graphical file dialog.
1159 *** LessTif: Problems in Emacs built with LessTif.
1161 The problems seem to depend on the version of LessTif and the Motif
1162 emulation for which it is set up.
1164 Only the Motif 1.2 emulation seems to be stable enough in LessTif.
1165 LessTif 0.92-17's Motif 1.2 emulation seems to work okay on FreeBSD.
1166 On GNU/Linux systems, lesstif-0.92.6 configured with "./configure
1167 --enable-build-12 --enable-default-12" is reported to be the most
1168 successful. The binary GNU/Linux package
1169 lesstif-devel-0.92.0-1.i386.rpm was reported to have problems with
1172 On some systems, even with Motif 1.2 emulation, Emacs occasionally
1173 locks up, grabbing all mouse and keyboard events. We still don't know
1174 what causes these problems; they are not reproducible by Emacs developers.
1176 *** Motif: The Motif version of Emacs paints the screen a solid color.
1178 This has been observed to result from the following X resource:
1180 Emacs*default.attributeFont: -*-courier-medium-r-*-*-*-140-*-*-*-*-iso8859-*
1182 That the resource has this effect indicates a bug in something, but we
1183 do not yet know what. If it is an Emacs bug, we hope someone can
1184 explain what the bug is so we can fix it. In the mean time, removing
1185 the resource prevents the problem.
1187 ** General X problems
1189 *** Redisplay using X11 is much slower than previous Emacs versions.
1191 We've noticed that certain X servers draw the text much slower when
1192 scroll bars are on the left. We don't know why this happens. If this
1193 happens to you, you can work around it by putting the scroll bars
1194 on the right (as they were in Emacs 19).
1196 Here's how to do this:
1198 (set-scroll-bar-mode 'right)
1200 If you're not sure whether (or how much) this problem affects you,
1201 try that and see how much difference it makes. To set things back
1204 (set-scroll-bar-mode 'left)
1206 *** Error messages about undefined colors on X.
1208 The messages might say something like this:
1210 Unable to load color "grey95"
1212 (typically, in the `*Messages*' buffer), or something like this:
1214 Error while displaying tooltip: (error Undefined color lightyellow)
1216 These problems could happen if some other X program has used up too
1217 many colors of the X palette, leaving Emacs with insufficient system
1218 resources to load all the colors it needs.
1220 A solution is to exit the offending X programs before starting Emacs.
1222 "undefined color" messages can also occur if the RgbPath entry in the
1223 X configuration file is incorrect, or the rgb.txt file is not where
1224 X expects to find it.
1226 *** Improving performance with slow X connections.
1228 There are several ways to improve this performance, any subset of which can
1229 be carried out at the same time:
1231 1) If you don't need X Input Methods (XIM) for entering text in some
1232 language you use, you can improve performance on WAN links by using
1233 the X resource useXIM to turn off use of XIM. This does not affect
1234 the use of Emacs' own input methods, which are part of the Leim
1237 2) If the connection is very slow, you might also want to consider
1238 switching off scroll bars, menu bar, and tool bar. Adding the
1239 following forms to your .emacs file will accomplish that, but only
1240 after the initial frame is displayed:
1242 (scroll-bar-mode -1)
1246 For still quicker startup, put these X resources in your .Xdefaults
1249 Emacs.verticalScrollBars: off
1253 3) Use ssh to forward the X connection, and enable compression on this
1254 forwarded X connection (ssh -XC remotehostname emacs ...).
1256 4) Use lbxproxy on the remote end of the connection. This is an interface
1257 to the low bandwidth X extension in most modern X servers, which
1258 improves performance dramatically, at the slight expense of correctness
1259 of the X protocol. lbxproxy achieves the performance gain by grouping
1260 several X requests in one TCP packet and sending them off together,
1261 instead of requiring a round-trip for each X request in a separate
1262 packet. The switches that seem to work best for emacs are:
1263 -noatomsfile -nowinattr -cheaterrors -cheatevents
1264 Note that the -nograbcmap option is known to cause problems.
1265 For more about lbxproxy, see:
1266 http://www.xfree86.org/4.3.0/lbxproxy.1.html
1268 5) If copying and killing is slow, try to disable the interaction with the
1269 native system's clipboard by adding these lines to your .emacs file:
1270 (setq interprogram-cut-function nil)
1271 (setq interprogram-paste-function nil)
1273 *** Emacs gives the error, Couldn't find per display information.
1275 This can result if the X server runs out of memory because Emacs uses
1276 a large number of fonts. On systems where this happens, C-h h is
1279 We do not know of a way to prevent the problem.
1281 *** Emacs does not notice when you release the mouse.
1283 There are reports that this happened with (some) Microsoft mice and
1284 that replacing the mouse made it stop.
1286 *** You can't select from submenus (in the X toolkit version).
1288 On certain systems, mouse-tracking and selection in top-level menus
1289 works properly with the X toolkit, but neither of them works when you
1290 bring up a submenu (such as Bookmarks or Compare or Apply Patch, in
1293 This works on most systems. There is speculation that the failure is
1294 due to bugs in old versions of X toolkit libraries, but no one really
1295 knows. If someone debugs this and finds the precise cause, perhaps a
1296 workaround can be found.
1298 *** An error message such as `X protocol error: BadMatch (invalid
1299 parameter attributes) on protocol request 93'.
1301 This comes from having an invalid X resource, such as
1303 (which is invalid because it specifies a color name for something
1304 that isn't a color.)
1306 The fix is to correct your X resources.
1308 *** Slow startup on X11R6 with X windows.
1310 If Emacs takes two minutes to start up on X11R6, see if your X
1311 resources specify any Adobe fonts. That causes the type-1 font
1312 renderer to start up, even if the font you asked for is not a type-1
1315 One way to avoid this problem is to eliminate the type-1 fonts from
1316 your font path, like this:
1318 xset -fp /usr/X11R6/lib/X11/fonts/Type1/
1320 *** Pull-down menus appear in the wrong place, in the toolkit version of Emacs.
1322 An X resource of this form can cause the problem:
1324 Emacs*geometry: 80x55+0+0
1326 This resource is supposed to apply, and does apply, to the menus
1327 individually as well as to Emacs frames. If that is not what you
1328 want, rewrite the resource.
1330 To check thoroughly for such resource specifications, use `xrdb
1331 -query' to see what resources the X server records, and also look at
1332 the user's ~/.Xdefaults and ~/.Xdefaults-* files.
1334 *** Emacs running under X Windows does not handle mouse clicks.
1335 *** `emacs -geometry 80x20' finds a file named `80x20'.
1337 One cause of such problems is having (setq term-file-prefix nil) in
1338 your .emacs file. Another cause is a bad value of EMACSLOADPATH in
1341 *** X Windows doesn't work if DISPLAY uses a hostname.
1343 People have reported kernel bugs in certain systems that cause Emacs
1344 not to work with X Windows if DISPLAY is set using a host name. But
1345 the problem does not occur if DISPLAY is set to `unix:0.0'. I think
1346 the bug has to do with SIGIO or FIONREAD.
1348 You may be able to compensate for the bug by doing (set-input-mode nil nil).
1349 However, that has the disadvantage of turning off interrupts, so that
1350 you are unable to quit out of a Lisp program by typing C-g.
1352 *** Prevent double pastes in X
1354 The problem: a region, such as a command, is pasted twice when you copy
1355 it with your mouse from GNU Emacs to an xterm or an RXVT shell in X.
1356 The solution: try the following in your X configuration file,
1357 /etc/X11/xorg.conf This should enable both PS/2 and USB mice for
1358 single copies. You do not need any other drivers or options.
1360 Section "InputDevice"
1361 Identifier "Generic Mouse"
1363 Option "Device" "/dev/input/mice"
1366 *** Emacs is slow to exit in X
1368 After you use e.g. C-x C-c to exit, it takes many seconds before the
1369 Emacs window disappears. If Emacs was started from a terminal, you
1372 Error saving to X clipboard manager.
1373 If the problem persists, set `x-select-enable-clipboard-manager' to nil.
1375 As the message suggests, this problem occurs when Emacs thinks you
1376 have a clipboard manager program running, but has trouble contacting it.
1377 If you don't want to use a clipboard manager, you can set the
1378 suggested variable. Or you can make Emacs not wait so long by
1379 reducing the value of `x-selection-timeout', either in .emacs or with
1382 Sometimes this problem is due to a bug in your clipboard manager.
1383 Updating to the latest version of the manager can help.
1384 For example, in the Xfce 4.8 desktop environment, the clipboard
1385 manager in versions of xfce4-settings-helper before 4.8.2 is buggy;
1386 https://bugzilla.xfce.org/show_bug.cgi?id=7588 .
1388 * Runtime problems on character terminals
1390 ** The meta key does not work on xterm.
1391 Typing M-x rings the terminal bell, and inserts a string like ";120~".
1392 For recent xterm versions (>= 216), Emacs uses xterm's modifyOtherKeys
1393 feature to generate strings for key combinations that are not
1394 otherwise usable. One circumstance in which this can cause problems
1395 is if you have specified the X resource
1397 xterm*VT100.Translations
1399 to contain translations that use the meta key. Then xterm will not
1400 use meta in modified function-keys, which confuses Emacs. To fix
1401 this, you can remove the X resource or put this in your init file:
1403 (xterm-remove-modify-other-keys)
1405 ** Emacs spontaneously displays "I-search: " at the bottom of the screen.
1407 This means that Control-S/Control-Q (XON/XOFF) "flow control" is being
1408 used. C-s/C-q flow control is bad for Emacs editors because it takes
1409 away C-s and C-q as user commands. Since editors do not output long
1410 streams of text without user commands, there is no need for a
1411 user-issuable "stop output" command in an editor; therefore, a
1412 properly designed flow control mechanism would transmit all possible
1413 input characters without interference. Designing such a mechanism is
1414 easy, for a person with at least half a brain.
1416 There are three possible reasons why flow control could be taking place:
1418 1) Terminal has not been told to disable flow control
1419 2) Insufficient padding for the terminal in use
1420 3) Some sort of terminal concentrator or line switch is responsible
1422 First of all, many terminals have a set-up mode which controls whether
1423 they generate XON/XOFF flow control characters. This must be set to
1424 "no XON/XOFF" in order for Emacs to work. (For example, on a VT220
1425 you may select "No XOFF" in the setup menu.) Sometimes there is an
1426 escape sequence that the computer can send to turn flow control off
1427 and on. If so, perhaps the termcap `ti' string should turn flow
1428 control off, and the `te' string should turn it on.
1430 Once the terminal has been told "no flow control", you may find it
1431 needs more padding. The amount of padding Emacs sends is controlled
1432 by the termcap entry for the terminal in use, and by the output baud
1433 rate as known by the kernel. The shell command `stty' will print
1434 your output baud rate; `stty' with suitable arguments will set it if
1435 it is wrong. Setting to a higher speed causes increased padding. If
1436 the results are wrong for the correct speed, there is probably a
1437 problem in the termcap entry. You must speak to a local Unix wizard
1438 to fix this. Perhaps you are just using the wrong terminal type.
1440 For terminals that lack a "no flow control" mode, sometimes just
1441 giving lots of padding will prevent actual generation of flow control
1442 codes. You might as well try it.
1444 If you are really unlucky, your terminal is connected to the computer
1445 through a concentrator which sends XON/XOFF flow control to the
1446 computer, or it insists on sending flow control itself no matter how
1447 much padding you give it. Unless you can figure out how to turn flow
1448 control off on this concentrator (again, refer to your local wizard),
1449 you are screwed! You should have the terminal or concentrator
1450 replaced with a properly designed one. In the mean time, some drastic
1451 measures can make Emacs semi-work.
1453 You can make Emacs ignore C-s and C-q and let the operating system
1454 handle them. To do this on a per-session basis, just type M-x
1455 enable-flow-control RET. You will see a message that C-\ and C-^ are
1456 now translated to C-s and C-q. (Use the same command M-x
1457 enable-flow-control to turn *off* this special mode. It toggles flow
1460 If C-\ and C-^ are inconvenient for you (for example, if one of them
1461 is the escape character of your terminal concentrator), you can choose
1462 other characters by setting the variables flow-control-c-s-replacement
1463 and flow-control-c-q-replacement. But choose carefully, since all
1464 other control characters are already used by emacs.
1466 IMPORTANT: if you type C-s by accident while flow control is enabled,
1467 Emacs output will freeze, and you will have to remember to type C-q in
1470 If you work in an environment where a majority of terminals of a
1471 certain type are flow control hobbled, you can use the function
1472 `enable-flow-control-on' to turn on this flow control avoidance scheme
1473 automatically. Here is an example:
1475 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1477 If this isn't quite correct (e.g. you have a mixture of flow-control hobbled
1478 and good vt200 terminals), you can still run enable-flow-control
1481 I have no intention of ever redesigning the Emacs command set for the
1482 assumption that terminals use C-s/C-q flow control. XON/XOFF flow
1483 control technique is a bad design, and terminals that need it are bad
1484 merchandise and should not be purchased. Now that X is becoming
1485 widespread, XON/XOFF seems to be on the way out. If you can get some
1486 use out of GNU Emacs on inferior terminals, more power to you, but I
1487 will not make Emacs worse for properly designed systems for the sake
1488 of inferior systems.
1490 ** Control-S and Control-Q commands are ignored completely.
1492 For some reason, your system is using brain-damaged C-s/C-q flow
1493 control despite Emacs's attempts to turn it off. Perhaps your
1494 terminal is connected to the computer through a concentrator
1495 that wants to use flow control.
1497 You should first try to tell the concentrator not to use flow control.
1498 If you succeed in this, try making the terminal work without
1499 flow control, as described in the preceding section.
1501 If that line of approach is not successful, map some other characters
1502 into C-s and C-q using keyboard-translate-table. The example above
1503 shows how to do this with C-^ and C-\.
1505 ** Screen is updated wrong, but only on one kind of terminal.
1507 This could mean that the termcap entry you are using for that
1508 terminal is wrong, or it could mean that Emacs has a bug handing
1509 the combination of features specified for that terminal.
1511 The first step in tracking this down is to record what characters
1512 Emacs is sending to the terminal. Execute the Lisp expression
1513 (open-termscript "./emacs-script") to make Emacs write all
1514 terminal output into the file ~/emacs-script as well; then do
1515 what makes the screen update wrong, and look at the file
1516 and decode the characters using the manual for the terminal.
1517 There are several possibilities:
1519 1) The characters sent are correct, according to the terminal manual.
1521 In this case, there is no obvious bug in Emacs, and most likely you
1522 need more padding, or possibly the terminal manual is wrong.
1524 2) The characters sent are incorrect, due to an obscure aspect
1525 of the terminal behavior not described in an obvious way by termcap.
1527 This case is hard. It will be necessary to think of a way for
1528 Emacs to distinguish between terminals with this kind of behavior
1529 and other terminals that behave subtly differently but are
1530 classified the same by termcap; or else find an algorithm for
1531 Emacs to use that avoids the difference. Such changes must be
1532 tested on many kinds of terminals.
1534 3) The termcap entry is wrong.
1536 See the file etc/TERMS for information on changes
1537 that are known to be needed in commonly used termcap entries
1538 for certain terminals.
1540 4) The characters sent are incorrect, and clearly cannot be
1541 right for any terminal with the termcap entry you were using.
1543 This is unambiguously an Emacs bug, and can probably be fixed
1544 in termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c.
1546 ** Control-S and Control-Q commands are ignored completely on a net connection.
1548 Some versions of rlogin (and possibly telnet) do not pass flow
1549 control characters to the remote system to which they connect.
1550 On such systems, emacs on the remote system cannot disable flow
1551 control on the local system. Sometimes `rlogin -8' will avoid this problem.
1553 One way to cure this is to disable flow control on the local host
1554 (the one running rlogin, not the one running rlogind) using the
1555 stty command, before starting the rlogin process. On many systems,
1556 "stty start u stop u" will do this. On some systems, use
1557 "stty -ixon" instead.
1559 Some versions of tcsh will prevent even this from working. One way
1560 around this is to start another shell before starting rlogin, and
1561 issue the stty command to disable flow control from that shell.
1563 If none of these methods work, the best solution is to type
1564 M-x enable-flow-control at the beginning of your emacs session, or
1565 if you expect the problem to continue, add a line such as the
1566 following to your .emacs (on the host running rlogind):
1568 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1570 See the entry about spontaneous display of I-search (above) for more info.
1572 ** Output from Control-V is slow.
1574 On many bit-map terminals, scrolling operations are fairly slow.
1575 Often the termcap entry for the type of terminal in use fails
1576 to inform Emacs of this. The two lines at the bottom of the screen
1577 before a Control-V command are supposed to appear at the top after
1578 the Control-V command. If Emacs thinks scrolling the lines is fast,
1579 it will scroll them to the top of the screen.
1581 If scrolling is slow but Emacs thinks it is fast, the usual reason is
1582 that the termcap entry for the terminal you are using does not
1583 specify any padding time for the `al' and `dl' strings. Emacs
1584 concludes that these operations take only as much time as it takes to
1585 send the commands at whatever line speed you are using. You must
1586 fix the termcap entry to specify, for the `al' and `dl', as much
1587 time as the operations really take.
1589 Currently Emacs thinks in terms of serial lines which send characters
1590 at a fixed rate, so that any operation which takes time for the
1591 terminal to execute must also be padded. With bit-map terminals
1592 operated across networks, often the network provides some sort of
1593 flow control so that padding is never needed no matter how slow
1594 an operation is. You must still specify a padding time if you want
1595 Emacs to realize that the operation takes a long time. This will
1596 cause padding characters to be sent unnecessarily, but they do
1597 not really cost much. They will be transmitted while the scrolling
1598 is happening and then discarded quickly by the terminal.
1600 Most bit-map terminals provide commands for inserting or deleting
1601 multiple lines at once. Define the `AL' and `DL' strings in the
1602 termcap entry to say how to do these things, and you will have
1603 fast output without wasted padding characters. These strings should
1604 each contain a single %-spec saying how to send the number of lines
1605 to be scrolled. These %-specs are like those in the termcap
1608 You should also define the `IC' and `DC' strings if your terminal
1609 has a command to insert or delete multiple characters. These
1610 take the number of positions to insert or delete as an argument.
1612 A `cs' string to set the scrolling region will reduce the amount
1613 of motion you see on the screen when part of the screen is scrolled.
1615 ** You type Control-H (Backspace) expecting to delete characters.
1617 Put `stty dec' in your .login file and your problems will disappear
1620 The choice of Backspace for erasure was based on confusion, caused by
1621 the fact that backspacing causes erasure (later, when you type another
1622 character) on most display terminals. But it is a mistake. Deletion
1623 of text is not the same thing as backspacing followed by failure to
1624 overprint. I do not wish to propagate this confusion by conforming
1627 For this reason, I believe `stty dec' is the right mode to use,
1628 and I have designed Emacs to go with that. If there were a thousand
1629 other control characters, I would define Control-h to delete as well;
1630 but there are not very many other control characters, and I think
1631 that providing the most mnemonic possible Help character is more
1632 important than adapting to people who don't use `stty dec'.
1634 If you are obstinate about confusing buggy overprinting with deletion,
1635 you can redefine Backspace in your .emacs file:
1636 (global-set-key "\b" 'delete-backward-char)
1637 You can probably access help-command via f1.
1639 ** Colors are not available on a tty or in xterm.
1641 Emacs 21 supports colors on character terminals and terminal
1642 emulators, but this support relies on the terminfo or termcap database
1643 entry to specify that the display supports color. Emacs looks at the
1644 "Co" capability for the terminal to find out how many colors are
1645 supported; it should be non-zero to activate the color support within
1646 Emacs. (Most color terminals support 8 or 16 colors.) If your system
1647 uses terminfo, the name of the capability equivalent to "Co" is
1650 In addition to the "Co" capability, Emacs needs the "op" (for
1651 ``original pair'') capability, which tells how to switch the terminal
1652 back to the default foreground and background colors. Emacs will not
1653 use colors if this capability is not defined. If your terminal entry
1654 doesn't provide such a capability, try using the ANSI standard escape
1655 sequence \E[00m (that is, define a new termcap/terminfo entry and make
1656 it use your current terminal's entry plus \E[00m for the "op"
1659 Finally, the "NC" capability (terminfo name: "ncv") tells Emacs which
1660 attributes cannot be used with colors. Setting this capability
1661 incorrectly might have the effect of disabling colors; try setting
1662 this capability to `0' (zero) and see if that helps.
1664 Emacs uses the database entry for the terminal whose name is the value
1665 of the environment variable TERM. With `xterm', a common terminal
1666 entry that supports color is `xterm-color', so setting TERM's value to
1667 `xterm-color' might activate the color support on an xterm-compatible
1670 Beginning with version 22.1, Emacs supports the --color command-line
1671 option which may be used to force Emacs to use one of a few popular
1672 modes for getting colors on a tty. For example, --color=ansi8 sets up
1673 for using the ANSI-standard escape sequences that support 8 colors.
1675 Some modes do not use colors unless you turn on the Font-lock mode.
1676 Some people have long ago set their `~/.emacs' files to turn on
1677 Font-lock on X only, so they won't see colors on a tty. The
1678 recommended way of turning on Font-lock is by typing "M-x
1679 global-font-lock-mode RET" or by customizing the variable
1680 `global-font-lock-mode'.
1682 ** Unexpected characters inserted into the buffer when you start Emacs.
1683 See eg http://debbugs.gnu.org/11129
1685 This can happen when you start Emacs in -nw mode in an Xterm.
1686 For example, in the *scratch* buffer, you might see something like:
1690 This is more likely to happen if you are using Emacs over a slow
1691 connection, and begin typing before Emacs is ready to respond.
1693 This occurs when Emacs tries to query the terminal to see what
1694 capabilities it supports, and gets confused by the answer.
1695 To avoid it, set xterm-extra-capabilities to a value other than
1696 `check' (the default). See that variable's documentation (in
1697 term/xterm.el) for more details.
1699 * Runtime problems specific to individual Unix variants
1703 *** GNU/Linux: Process output is corrupted.
1705 There is a bug in Linux kernel 2.6.10 PTYs that can cause emacs to
1706 read corrupted process output.
1708 *** GNU/Linux: Remote access to CVS with SSH causes file corruption.
1710 If you access a remote CVS repository via SSH, files may be corrupted
1711 due to bad interaction between CVS, SSH, and libc.
1713 To fix the problem, save the following script into a file, make it
1714 executable, and set CVS_RSH environment variable to the file name of
1718 exec 2> >(exec cat >&2 2>/dev/null)
1721 *** GNU/Linux: Truncated svn annotate output with SSH.
1722 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=7791
1724 The symptoms are: you are accessing a svn repository over SSH.
1725 You use vc-annotate on a large (several thousand line) file, and the
1726 result is truncated around the 1000 line mark. It works fine with
1727 other access methods (eg http), or from outside Emacs.
1729 This may be a similar libc/SSH issue to the one mentioned above for CVS.
1730 A similar workaround seems to be effective: create a script with the
1731 same contents as the one used above for CVS_RSH, and set the SVN_SSH
1732 environment variable to point to it.
1734 *** GNU/Linux: On Linux-based GNU systems using libc versions 5.4.19 through
1735 5.4.22, Emacs crashes at startup with a segmentation fault.
1737 This problem happens if libc defines the symbol __malloc_initialized.
1738 One known solution is to upgrade to a newer libc version. 5.4.33 is
1741 *** GNU/Linux: After upgrading to a newer version of Emacs,
1742 the Meta key stops working.
1744 This was reported to happen on a GNU/Linux system distributed by
1745 Mandrake. The reason is that the previous version of Emacs was
1746 modified by Mandrake to make the Alt key act as the Meta key, on a
1747 keyboard where the Windows key is the one which produces the Meta
1748 modifier. A user who started using a newer version of Emacs, which
1749 was not hacked by Mandrake, expected the Alt key to continue to act as
1750 Meta, and was astonished when that didn't happen.
1752 The solution is to find out what key on your keyboard produces the Meta
1753 modifier, and use that key instead. Try all of the keys to the left
1754 and to the right of the space bar, together with the `x' key, and see
1755 which combination produces "M-x" in the echo area. You can also use
1756 the `xmodmap' utility to show all the keys which produce a Meta
1759 xmodmap -pk | egrep -i "meta|alt"
1761 A more convenient way of finding out which keys produce a Meta modifier
1762 is to use the `xkbprint' utility, if it's available on your system:
1764 xkbprint 0:0 /tmp/k.ps
1766 This produces a PostScript file `/tmp/k.ps' with a picture of your
1767 keyboard; printing that file on a PostScript printer will show what
1768 keys can serve as Meta.
1770 The `xkeycaps' also shows a visual representation of the current
1771 keyboard settings. It also allows to modify them.
1773 *** GNU/Linux: slow startup on Linux-based GNU systems.
1775 People using systems based on the Linux kernel sometimes report that
1776 startup takes 10 to 15 seconds longer than `usual'.
1778 This is because Emacs looks up the host name when it starts.
1779 Normally, this takes negligible time; the extra delay is due to
1780 improper system configuration. This problem can occur for both
1781 networked and non-networked machines.
1783 Here is how to fix the configuration. It requires being root.
1785 **** Networked Case.
1787 First, make sure the files `/etc/hosts' and `/etc/host.conf' both
1788 exist. The first line in the `/etc/hosts' file should look like this
1789 (replace HOSTNAME with your host name):
1793 Also make sure that the `/etc/host.conf' files contains the following
1799 Any changes, permanent and temporary, to the host name should be
1800 indicated in the `/etc/hosts' file, since it acts a limited local
1801 database of addresses and names (e.g., some SLIP connections
1802 dynamically allocate ip addresses).
1804 **** Non-Networked Case.
1806 The solution described in the networked case applies here as well.
1807 However, if you never intend to network your machine, you can use a
1808 simpler solution: create an empty `/etc/host.conf' file. The command
1809 `touch /etc/host.conf' suffices to create the file. The `/etc/hosts'
1810 file is not necessary with this approach.
1812 *** GNU/Linux: Emacs on a tty switches the cursor to large blinking block.
1814 This was reported to happen on some GNU/Linux systems which use
1815 ncurses version 5.0, but could be relevant for other versions as well.
1816 These versions of ncurses come with a `linux' terminfo entry, where
1817 the "cvvis" capability (termcap "vs") is defined as "\E[?25h\E[?8c"
1818 (show cursor, change size). This escape sequence switches on a
1819 blinking hardware text-mode cursor whose size is a full character
1820 cell. This blinking cannot be stopped, since a hardware cursor
1823 A work-around is to redefine the "cvvis" capability so that it
1824 enables a *software* cursor. The software cursor works by inverting
1825 the colors of the character at point, so what you see is a block
1826 cursor that doesn't blink. For this to work, you need to redefine
1827 the "cnorm" capability as well, so that it operates on the software
1828 cursor instead of the hardware cursor.
1830 To this end, run "infocmp linux > linux-term", edit the file
1831 `linux-term' to make both the "cnorm" and "cvvis" capabilities send
1832 the sequence "\E[?25h\E[?17;0;64c", and then run "tic linux-term" to
1833 produce a modified terminfo entry.
1835 Alternatively, if you want a blinking underscore as your Emacs cursor,
1836 change the "cvvis" capability to send the "\E[?25h\E[?0c" command.
1838 *** GNU/Linux: Error messages `internal facep []' happen on GNU/Linux systems.
1840 There is a report that replacing libc.so.5.0.9 with libc.so.5.2.16
1841 caused this to start happening. People are not sure why, but the
1842 problem seems unlikely to be in Emacs itself. Some suspect that it
1843 is actually Xlib which won't work with libc.so.5.2.16.
1845 Using the old library version is a workaround.
1849 *** FreeBSD 2.1.5: useless symbolic links remain in /tmp or other
1850 directories that have the +t bit.
1852 This is because of a kernel bug in FreeBSD 2.1.5 (fixed in 2.2).
1853 Emacs uses symbolic links to implement file locks. In a directory
1854 with +t bit, the directory owner becomes the owner of the symbolic
1855 link, so that it cannot be removed by anyone else.
1857 If you don't like those useless links, you can let Emacs not to using
1858 file lock by adding #undef CLASH_DETECTION to config.h.
1860 *** FreeBSD: Getting a Meta key on the console.
1862 By default, neither Alt nor any other key acts as a Meta key on
1863 FreeBSD, but this can be changed using kbdcontrol(1). Dump the
1864 current keymap to a file with the command
1866 $ kbdcontrol -d >emacs.kbd
1868 Edit emacs.kbd, and give the key you want to be the Meta key the
1869 definition `meta'. For instance, if your keyboard has a ``Windows''
1870 key with scan code 105, change the line for scan code 105 in emacs.kbd
1873 105 meta meta meta meta meta meta meta meta O
1875 to make the Windows key the Meta key. Load the new keymap with
1877 $ kbdcontrol -l emacs.kbd
1881 *** HP/UX : Shell mode gives the message, "`tty`: Ambiguous".
1883 christos@theory.tn.cornell.edu says:
1885 The problem is that in your .cshrc you have something that tries to
1886 execute `tty`. If you are not running the shell on a real tty then
1887 tty will print "not a tty". Csh expects one word in some places,
1888 but tty is giving it back 3.
1890 The solution is to add a pair of quotes around `tty` to make it a single
1893 if (`tty` == "/dev/console")
1895 should be changed to:
1897 if ("`tty`" == "/dev/console")
1899 Even better, move things that set up terminal sections out of .cshrc
1902 *** HP/UX: `Pid xxx killed due to text modification or page I/O error'.
1904 On HP/UX, you can get that error when the Emacs executable is on an NFS
1905 file system. HP/UX responds this way if it tries to swap in a page and
1906 does not get a response from the server within a timeout whose default
1907 value is just ten seconds.
1909 If this happens to you, extend the timeout period.
1911 *** HP/UX: The right Alt key works wrong on German HP keyboards (and perhaps
1912 other non-English HP keyboards too).
1914 This is because HP-UX defines the modifiers wrong in X. Here is a
1915 shell script to fix the problem; be sure that it is run after VUE
1916 configures the X server.
1918 xmodmap 2> /dev/null - << EOF
1919 keysym Alt_L = Meta_L
1920 keysym Alt_R = Meta_R
1925 keysym Mode_switch = NoSymbol
1927 keysym Meta_R = Mode_switch
1928 add mod2 = Mode_switch
1931 *** HP/UX: "Cannot find callback list" messages from dialog boxes in
1932 Emacs built with Motif.
1934 This problem resulted from a bug in GCC 2.4.5. Newer GCC versions
1935 such as 2.7.0 fix the problem.
1937 *** HP/UX: Emacs does not recognize the AltGr key.
1939 To fix this, set up a file ~/.dt/sessions/sessionetc with executable
1940 rights, containing this text:
1942 --------------------------------
1943 xmodmap 2> /dev/null - << EOF
1944 keysym Alt_L = Meta_L
1945 keysym Alt_R = Meta_R
1950 keysym Mode_switch = NoSymbol
1952 keysym Meta_R = Mode_switch
1953 add mod2 = Mode_switch
1955 --------------------------------
1957 *** HP/UX 11.0: Emacs makes HP/UX 11.0 crash.
1959 This is a bug in HPUX; HPUX patch PHKL_16260 is said to fix it.
1963 *** AIX: Trouble using ptys.
1965 People often install the pty devices on AIX incorrectly.
1966 Use `smit pty' to reinstall them properly.
1968 *** AIXterm: Your Delete key sends a Backspace to the terminal.
1970 The solution is to include in your .Xdefaults the lines:
1972 *aixterm.Translations: #override <Key>BackSpace: string(0x7f)
1973 aixterm*ttyModes: erase ^?
1975 This makes your Backspace key send DEL (ASCII 127).
1977 *** AIX: If linking fails because libXbsd isn't found, check if you
1978 are compiling with the system's `cc' and CFLAGS containing `-O5'. If
1979 so, you have hit a compiler bug. Please make sure to re-configure
1980 Emacs so that it isn't compiled with `-O5'.
1982 *** AIX 4.3.x or 4.4: Compiling fails.
1984 This could happen if you use /bin/c89 as your compiler, instead of
1985 the default `cc'. /bin/c89 treats certain warnings, such as benign
1986 redefinitions of macros, as errors, and fails the build. A solution
1987 is to use the default compiler `cc'.
1989 *** AIX 4: Some programs fail when run in a Shell buffer
1990 with an error message like No terminfo entry for "unknown".
1992 On AIX, many terminal type definitions are not installed by default.
1993 `unknown' is one of them. Install the "Special Generic Terminal
1994 Definitions" to make them defined.
1998 We list bugs in current versions here. See also the section on legacy
2001 *** On Solaris, C-x doesn't get through to Emacs when you use the console.
2003 This is a Solaris feature (at least on Intel x86 cpus). Type C-r
2004 C-r C-t, to toggle whether C-x gets through to Emacs.
2006 *** Problem with remote X server on Suns.
2008 On a Sun, running Emacs on one machine with the X server on another
2009 may not work if you have used the unshared system libraries. This
2010 is because the unshared libraries fail to use YP for host name lookup.
2011 As a result, the host name you specify may not be recognized.
2013 *** Solaris 2.6: Emacs crashes with SIGBUS or SIGSEGV on Solaris after you delete a frame.
2015 We suspect that this is a bug in the X libraries provided by
2016 Sun. There is a report that one of these patches fixes the bug and
2017 makes the problem stop:
2019 105216-01 105393-01 105518-01 105621-01 105665-01 105615-02 105216-02
2020 105667-01 105401-08 105615-03 105621-02 105686-02 105736-01 105755-03
2021 106033-01 105379-01 105786-01 105181-04 105379-03 105786-04 105845-01
2022 105284-05 105669-02 105837-01 105837-02 105558-01 106125-02 105407-01
2024 Another person using a newer system (kernel patch level Generic_105181-06)
2025 suspects that the bug was fixed by one of these more recent patches:
2027 106040-07 SunOS 5.6: X Input & Output Method patch
2028 106222-01 OpenWindows 3.6: filemgr (ff.core) fixes
2029 105284-12 Motif 1.2.7: sparc Runtime library patch
2031 *** Solaris 7 or 8: Emacs reports a BadAtom error (from X)
2033 This happens when Emacs was built on some other version of Solaris.
2034 Rebuild it on Solaris 8.
2036 *** When using M-x dbx with the SparcWorks debugger, the `up' and `down'
2037 commands do not move the arrow in Emacs.
2039 You can fix this by adding the following line to `~/.dbxinit':
2041 dbxenv output_short_file_name off
2043 *** On Solaris, CTRL-t is ignored by Emacs when you use
2044 the fr.ISO-8859-15 locale (and maybe other related locales).
2046 You can fix this by editing the file:
2048 /usr/openwin/lib/locale/iso8859-15/Compose
2050 Near the bottom there is a line that reads:
2052 Ctrl<t> <quotedbl> <Y> : "\276" threequarters
2056 Ctrl<T> <quotedbl> <Y> : "\276" threequarters
2058 Note the lower case <t>. Changing this line should make C-t work.
2060 *** On Solaris, Emacs fails to set menu-bar-update-hook on startup, with error
2061 "Error in menu-bar-update-hook: (error Point before start of properties)".
2062 This seems to be a GCC optimization bug that occurs for GCC 4.1.2 (-g
2063 and -g -O2) and GCC 4.2.3 (-g -O and -g -O2). You can fix this by
2064 compiling with GCC 4.2.3 or CC 5.7, with no optimizations.
2068 *** Irix 6.5: Emacs crashes on the SGI R10K, when compiled with GCC.
2070 This seems to be fixed in GCC 2.95.
2072 *** Irix: Trouble using ptys, or running out of ptys.
2074 The program mkpts (which may be in `/usr/adm' or `/usr/sbin') needs to
2075 be set-UID to root, or non-root programs like Emacs will not be able
2076 to allocate ptys reliably.
2078 * Runtime problems specific to MS-Windows
2080 ** PATH can contain unexpanded environment variables
2082 Old releases of TCC (version 9) and 4NT (up to version 8) do not correctly
2083 expand App Paths entries of type REG_EXPAND_SZ. When Emacs is run from TCC
2084 and such an entry exists for emacs.exe, exec-path will contain the
2085 unexpanded entry. This has been fixed in TCC 10. For more information,
2088 ** Setting w32-pass-rwindow-to-system and w32-pass-lwindow-to-system to nil
2089 does not prevent the Start menu from popping up when the left or right
2090 ``Windows'' key is pressed.
2092 This was reported to happen when XKeymacs is installed. At least with
2093 XKeymacs Version 3.47, deactivating XKeymacs when Emacs is active is
2094 not enough to avoid its messing with the keyboard input. Exiting
2095 XKeymacs completely is reported to solve the problem.
2097 ** Windows 95 and networking.
2099 To support server sockets, Emacs 22.1 loads ws2_32.dll. If this file
2100 is missing, all Emacs networking features are disabled.
2102 Old versions of Windows 95 may not have the required DLL. To use
2103 Emacs' networking features on Windows 95, you must install the
2104 "Windows Socket 2" update available from MicroSoft's support Web.
2106 ** Emacs exits with "X protocol error" when run with an X server for MS-Windows.
2108 A certain X server for Windows had a bug which caused this.
2109 Supposedly the newer 32-bit version of this server doesn't have the
2112 ** Emacs crashes when opening a file with a UNC path and rails-mode is loaded.
2114 Loading rails-mode seems to interfere with UNC path handling. This has been
2115 reported as a bug against both Emacs and rails-mode, so look for an updated
2116 rails-mode that avoids this crash, or avoid using UNC paths if using
2119 ** Known problems with the MS-Windows port of Emacs 22.3
2121 M-x term does not work on MS-Windows. TTY emulation on Windows is
2122 undocumented, and programs such as stty which are used on posix platforms
2123 to control tty emulation do not exist for native windows terminals.
2125 Using create-fontset-from-ascii-font or the --font startup parameter
2126 with a Chinese, Japanese or Korean font leads to display problems.
2127 Use a Latin-only font as your default font. If you want control over
2128 which font is used to display Chinese, Japanese or Korean character,
2129 use create-fontset-from-fontset-spec to define a fontset.
2131 Frames are not refreshed while the File or Font dialog or a pop-up menu
2132 is displayed. This also means help text for pop-up menus is not
2133 displayed at all. This is because message handling under Windows is
2134 synchronous, so we cannot handle repaint (or any other) messages while
2135 waiting for a system function to return the result of the dialog or
2136 pop-up menu interaction.
2138 Windows 95 and Windows NT up to version 4.0 do not support help text
2139 for menus. Help text is only available in later versions of Windows.
2141 When "ClearType" method is selected as the "method to smooth edges of
2142 screen fonts" (in Display Properties, Appearance tab, under
2143 "Effects"), there are various problems related to display of
2144 characters: Bold fonts can be hard to read, small portions of some
2145 characters could appear chopped, etc. This happens because, under
2146 ClearType, characters are drawn outside their advertised bounding box.
2147 Emacs 21 disabled the use of ClearType, whereas Emacs 22 allows it and
2148 has some code to enlarge the width of the bounding box. Apparently,
2149 this display feature needs more changes to get it 100% right. A
2150 workaround is to disable ClearType.
2152 There are problems with display if mouse-tracking is enabled and the
2153 mouse is moved off a frame, over another frame then back over the first
2154 frame. A workaround is to click the left mouse button inside the frame
2155 after moving back into it.
2157 Some minor flickering still persists during mouse-tracking, although
2158 not as severely as in 21.1.
2160 An inactive cursor remains in an active window after the Windows
2161 Manager driven switch of the focus, until a key is pressed.
2163 Windows input methods are not recognized by Emacs. However, some
2164 of these input methods cause the keyboard to send characters encoded
2165 in the appropriate coding system (e.g., ISO 8859-1 for Latin-1
2166 characters, ISO 8859-8 for Hebrew characters, etc.). To make these
2167 input methods work with Emacs, set the keyboard coding system to the
2168 appropriate value after you activate the Windows input method. For
2169 example, if you activate the Hebrew input method, type this:
2171 C-x RET k hebrew-iso-8bit RET
2173 (Emacs ought to recognize the Windows language-change event and set up
2174 the appropriate keyboard encoding automatically, but it doesn't do
2175 that yet.) In addition, to use these Windows input methods, you
2176 should set your "Language for non-Unicode programs" (on Windows XP,
2177 this is on the Advanced tab of Regional Settings) to the language of
2180 To bind keys that produce non-ASCII characters with modifiers, you
2181 must specify raw byte codes. For instance, if you want to bind
2182 META-a-grave to a command, you need to specify this in your `~/.emacs':
2184 (global-set-key [?\M-\340] ...)
2186 The above example is for the Latin-1 environment where the byte code
2187 of the encoded a-grave is 340 octal. For other environments, use the
2188 encoding appropriate to that environment.
2190 The %b specifier for format-time-string does not produce abbreviated
2191 month names with consistent widths for some locales on some versions
2192 of Windows. This is caused by a deficiency in the underlying system
2195 The function set-time-zone-rule gives incorrect results for many
2196 non-US timezones. This is due to over-simplistic handling of
2197 daylight savings switchovers by the Windows libraries.
2199 Files larger than 4GB cause overflow in the size (represented as a
2200 32-bit integer) reported by `file-attributes'. This affects Dired as
2201 well, since the Windows port uses a Lisp emulation of `ls' that relies
2202 on `file-attributes'.
2204 Sound playing is not supported with the `:data DATA' key-value pair.
2205 You _must_ use the `:file FILE' method.
2207 ** Typing Alt-Shift has strange effects on MS-Windows.
2209 This combination of keys is a command to change keyboard layout. If
2210 you proceed to type another non-modifier key before you let go of Alt
2211 and Shift, the Alt and Shift act as modifiers in the usual way. A
2212 more permanent work around is to change it to another key combination,
2213 or disable it in the "Regional and Language Options" applet of the
2214 Control Panel. (The exact sequence of mouse clicks in the "Regional
2215 and Language Options" applet needed to find the key combination that
2216 changes the keyboard layout depends on your Windows version; for XP,
2217 in the Languages tab, click "Details" and then "Key Settings".)
2219 ** Interrupting Cygwin port of Bash from Emacs doesn't work.
2221 Cygwin 1.x builds of the ported Bash cannot be interrupted from the
2222 MS-Windows version of Emacs. This is due to some change in the Bash
2223 port or in the Cygwin library which apparently make Bash ignore the
2224 keyboard interrupt event sent by Emacs to Bash. (Older Cygwin ports
2225 of Bash, up to b20.1, did receive SIGINT from Emacs.)
2227 ** Accessing remote files with ange-ftp hangs the MS-Windows version of Emacs.
2229 If the FTP client is the Cygwin port of GNU `ftp', this appears to be
2230 due to some bug in the Cygwin DLL or some incompatibility between it
2231 and the implementation of asynchronous subprocesses in the Windows
2232 port of Emacs. Specifically, some parts of the FTP server responses
2233 are not flushed out, apparently due to buffering issues, which
2236 The solution is to downgrade to an older version of the Cygwin DLL
2237 (version 1.3.2 was reported to solve the problem), or use the stock
2238 Windows FTP client, usually found in the `C:\WINDOWS' or 'C:\WINNT'
2239 directory. To force ange-ftp use the stock Windows client, set the
2240 variable `ange-ftp-ftp-program-name' to the absolute file name of the
2241 client's executable. For example:
2243 (setq ange-ftp-ftp-program-name "c:/windows/ftp.exe")
2245 If you want to stick with the Cygwin FTP client, you can work around
2246 this problem by putting this in your `.emacs' file:
2248 (setq ange-ftp-ftp-program-args '("-i" "-n" "-g" "-v" "--prompt" "")
2250 ** lpr commands don't work on MS-Windows with some cheap printers.
2252 This problem may also strike other platforms, but the solution is
2253 likely to be a global one, and not Emacs specific.
2255 Many cheap inkjet, and even some cheap laser printers, do not
2256 print plain text anymore, they will only print through graphical
2257 printer drivers. A workaround on MS-Windows is to use Windows' basic
2258 built in editor to print (this is possibly the only useful purpose it
2261 (setq printer-name "") ;; notepad takes the default
2262 (setq lpr-command "notepad") ;; notepad
2263 (setq lpr-switches nil) ;; not needed
2264 (setq lpr-printer-switch "/P") ;; run notepad as batch printer
2266 ** Antivirus software interacts badly with the MS-Windows version of Emacs.
2268 The usual manifestation of these problems is that subprocesses don't
2269 work or even wedge the entire system. In particular, "M-x shell RET"
2270 was reported to fail to work. But other commands also sometimes don't
2271 work when an antivirus package is installed.
2273 The solution is to switch the antivirus software to a less aggressive
2274 mode (e.g., disable the ``auto-protect'' feature), or even uninstall
2275 or disable it entirely.
2277 ** Pressing the mouse button on MS-Windows does not give a mouse-2 event.
2279 This is usually a problem with the mouse driver. Because most Windows
2280 programs do not do anything useful with the middle mouse button, many
2281 mouse drivers allow you to define the wheel press to do something
2282 different. Some drivers do not even have the option to generate a
2283 middle button press. In such cases, setting the wheel press to
2284 "scroll" sometimes works if you press the button twice. Trying a
2285 generic mouse driver might help.
2287 ** Scrolling the mouse wheel on MS-Windows always scrolls the top window.
2289 This is another common problem with mouse drivers. Instead of
2290 generating scroll events, some mouse drivers try to fake scroll bar
2291 movement. But they are not intelligent enough to handle multiple
2292 scroll bars within a frame. Trying a generic mouse driver might help.
2294 ** Mail sent through Microsoft Exchange in some encodings appears to be
2295 mangled and is not seen correctly in Rmail or Gnus. We don't know
2296 exactly what happens, but it isn't an Emacs problem in cases we've
2299 ** On MS-Windows, you cannot use the right-hand ALT key and the left-hand
2300 CTRL key together to type a Control-Meta character.
2302 This is a consequence of a misfeature beyond Emacs's control.
2304 Under Windows, the AltGr key on international keyboards generates key
2305 events with the modifiers Right-Alt and Left-Ctrl. Since Emacs cannot
2306 distinguish AltGr from an explicit Right-Alt and Left-Ctrl
2307 combination, whenever it sees Right-Alt and Left-Ctrl it assumes that
2308 AltGr has been pressed. The variable `w32-recognize-altgr' can be set
2309 to nil to tell Emacs that AltGr is really Ctrl and Alt.
2311 ** Under some X-servers running on MS-Windows, Emacs' display is incorrect.
2313 The symptoms are that Emacs does not completely erase blank areas of the
2314 screen during scrolling or some other screen operations (e.g., selective
2315 display or when killing a region). M-x recenter will cause the screen
2316 to be completely redisplayed and the "extra" characters will disappear.
2318 This is known to occur under Exceed 6, and possibly earlier versions
2319 as well; it is reportedly solved in version 6.2.0.16 and later. The
2320 problem lies in the X-server settings.
2322 There are reports that you can solve the problem with Exceed by
2323 running `Xconfig' from within NT, choosing "X selection", then
2324 un-checking the boxes "auto-copy X selection" and "auto-paste to X
2327 Of this does not work, please inform bug-gnu-emacs@gnu.org. Then
2328 please call support for your X-server and see if you can get a fix.
2329 If you do, please send it to bug-gnu-emacs@gnu.org so we can list it here.
2331 * Build-time problems
2335 *** The `configure' script doesn't find the jpeg library.
2337 There are reports that this happens on some systems because the linker
2338 by default only looks for shared libraries, but jpeg distribution by
2339 default only installs a nonshared version of the library, `libjpeg.a'.
2341 If this is the problem, you can configure the jpeg library with the
2342 `--enable-shared' option and then rebuild libjpeg. This produces a
2343 shared version of libjpeg, which you need to install. Finally, rerun
2344 the Emacs configure script, which should now find the jpeg library.
2345 Alternatively, modify the generated src/Makefile to link the .a file
2346 explicitly, and edit src/config.h to define HAVE_JPEG.
2348 *** `configure' warns ``accepted by the compiler, rejected by the preprocessor''.
2350 This indicates a mismatch between the C compiler and preprocessor that
2351 configure is using. For example, on Solaris 10 trying to use
2352 CC=/opt/SUNWspro/bin/cc (the Sun Studio compiler) together with
2353 CPP=/usr/ccs/lib/cpp can result in errors of this form (you may also
2354 see the error ``"/usr/include/sys/isa_defs.h", line 500: undefined control'').
2356 The solution is to tell configure to use the correct C preprocessor
2357 for your C compiler (CPP="/opt/SUNWspro/bin/cc -E" in the above
2362 *** Building Emacs over NFS fails with ``Text file busy''.
2364 This was reported to happen when building Emacs on a GNU/Linux system
2365 (Red Hat Linux 6.2) using a build directory automounted from Solaris
2366 (SunOS 5.6) file server, but it might not be limited to that
2367 configuration alone. Presumably, the NFS server doesn't commit the
2368 files' data to disk quickly enough, and the Emacs executable file is
2369 left ``busy'' for several seconds after Emacs has finished dumping
2370 itself. This causes the subsequent commands which invoke the dumped
2371 Emacs executable to fail with the above message.
2373 In some of these cases, a time skew between the NFS server and the
2374 machine where Emacs is built is detected and reported by GNU Make
2375 (it says that some of the files have modification time in the future).
2376 This might be a symptom of NFS-related problems.
2378 If the NFS server runs on Solaris, apply the Solaris patch 105379-05
2379 (Sunos 5.6: /kernel/misc/nfssrv patch). If that doesn't work, or if
2380 you have a different version of the OS or the NFS server, you can
2381 force the NFS server to use 1KB blocks, which was reported to fix the
2382 problem albeit at a price of slowing down file I/O. You can force 1KB
2383 blocks by specifying the "-o rsize=1024,wsize=1024" options to the
2384 `mount' command, or by adding ",rsize=1024,wsize=1024" to the mount
2385 options in the appropriate system configuration file, such as
2388 Alternatively, when Make fails due to this problem, you could wait for
2389 a few seconds and then invoke Make again. In one particular case,
2390 waiting for 10 or more seconds between the two Make invocations seemed
2391 to work around the problem.
2393 Similar problems can happen if your machine NFS-mounts a directory
2394 onto itself. Suppose the Emacs sources live in `/usr/local/src' and
2395 you are working on the host called `marvin'. Then an entry in the
2396 `/etc/fstab' file like the following is asking for trouble:
2398 marvin:/usr/local/src /usr/local/src ...options.omitted...
2400 The solution is to remove this line from `etc/fstab'.
2402 *** Building a 32-bit executable on a 64-bit GNU/Linux architecture.
2404 First ensure that the necessary 32-bit system libraries and include
2405 files are installed. Then use:
2407 env CC="gcc -m32" ./configure --build=i386-linux-gnu \
2408 --x-libraries=/usr/X11R6/lib
2410 (using the location of the 32-bit X libraries on your system).
2412 *** Building Emacs for Cygwin can fail with GCC 3
2414 As of Emacs 22.1, there have been stability problems with Cygwin
2415 builds of Emacs using GCC 3. Cygwin users are advised to use GCC 4.
2417 *** Building Emacs 23.3 and later will fail under Cygwin 1.5.19
2419 This is a consequence of a change to src/dired.c on 2010-07-27. The
2420 issue is that Cygwin 1.5.19 did not have d_ino in 'struct dirent'.
2423 http://lists.gnu.org/archive/html/emacs-devel/2010-07/msg01266.html
2425 *** Building the native MS-Windows port fails due to unresolved externals
2427 The linker error messages look like this:
2429 oo-spd/i386/ctags.o:ctags.c:(.text+0x156e): undefined reference to `_imp__re_set_syntax'
2430 collect2: ld returned 1 exit status
2432 This happens because GCC finds an incompatible header regex.h
2433 somewhere on the include path, before the version of regex.h supplied
2434 with Emacs. One such incompatible version of regex.h is part of the
2435 GnuWin32 Regex package.
2437 The solution is to remove the incompatible regex.h from the include
2438 path, when compiling Emacs. Alternatively, re-run the configure.bat
2439 script with the "-isystem C:/GnuWin32/include" switch (adapt for your
2440 system's place where you keep the GnuWin32 include files) -- this will
2441 cause the compiler to search headers in the directories specified by
2442 the Emacs Makefile _before_ it looks in the GnuWin32 include
2445 *** Building the native MS-Windows port with Cygwin GCC can fail.
2447 Emacs may not build using some Cygwin builds of GCC, such as Cygwin
2448 version 1.1.8, using the default configure settings. It appears to be
2449 necessary to specify the -mwin32 flag when compiling, and define
2450 __MSVCRT__, like so:
2452 configure --with-gcc --cflags -mwin32 --cflags -D__MSVCRT__
2454 *** Building the MS-Windows port fails with a CreateProcess failure.
2456 Some versions of mingw32 make on some versions of Windows do not seem
2457 to detect the shell correctly. Try "make SHELL=cmd.exe", or if that
2458 fails, try running make from Cygwin bash instead.
2460 *** Building `ctags' for MS-Windows with the MinGW port of GCC fails.
2462 This might happen due to a bug in the MinGW header assert.h, which
2463 defines the `assert' macro with a trailing semi-colon. The following
2464 patch to assert.h should solve this:
2466 *** include/assert.h.orig Sun Nov 7 02:41:36 1999
2467 --- include/assert.h Mon Jan 29 11:49:10 2001
2471 * If not debugging, assert does nothing.
2473 ! #define assert(x) ((void)0);
2475 #else /* debugging enabled */
2479 * If not debugging, assert does nothing.
2481 ! #define assert(x) ((void)0)
2483 #else /* debugging enabled */
2486 *** Building the MS-Windows port with Visual Studio 2005 fails.
2488 Microsoft no longer ships the single threaded version of the C library
2489 with their compiler, and the multithreaded static library is missing
2490 some functions that Microsoft have deemed non-threadsafe. The
2491 dynamically linked C library has all the functions, but there is a
2492 conflict between the versions of malloc in the DLL and in Emacs, which
2493 is not resolvable due to the way Windows does dynamic linking.
2495 We recommend the use of the MinGW port of GCC for compiling Emacs, as
2496 not only does it not suffer these problems, but it is also Free
2497 software like Emacs.
2499 *** Building the MS-Windows port with Visual Studio fails compiling emacs.rc
2501 If the build fails with the following message then the problem
2502 described here most likely applies:
2504 ../nt/emacs.rc(1) : error RC2176 : old DIB in icons\emacs.ico; pass it
2507 The Emacs icon contains a high resolution PNG icon for Vista, which is
2508 not recognized by older versions of the resource compiler. There are
2509 several workarounds for this problem:
2510 1. Use Free MinGW tools to compile, which do not have this problem.
2511 2. Install the latest Windows SDK.
2512 3. Replace emacs.ico with an older or edited icon.
2514 *** Building the MS-Windows port complains about unknown escape sequences.
2516 Errors and warnings can look like this:
2518 w32.c:1959:27: error: \x used with no following hex digits
2519 w32.c:1959:27: warning: unknown escape sequence '\i'
2521 This happens when paths using backslashes are passed to the compiler or
2522 linker (via -I and possibly other compiler flags); when these paths are
2523 included in source code, the backslashes are interpreted as escape sequences.
2524 See http://lists.gnu.org/archive/html/emacs-devel/2010-07/msg00995.html
2526 The fix is to use forward slashes in all paths passed to the compiler.
2530 *** Building Emacs with a system compiler fails to link because of an
2531 undefined symbol such as __eprintf which does not appear in Emacs.
2533 This can happen if some of the libraries linked into Emacs were built
2534 with GCC, but Emacs itself is being linked with a compiler other than
2535 GCC. Object files compiled with GCC might need some helper functions
2536 from libgcc.a, the library which comes with GCC, but the system
2537 compiler does not instruct the linker to search libgcc.a during the
2540 A solution is to link with GCC, like this:
2544 Since the .o object files already exist, this will not recompile Emacs
2545 with GCC, but just restart by trying again to link temacs.
2547 *** Sun with acc: Link failure when using acc on a Sun.
2549 To use acc, you need additional options just before the libraries, such as
2551 /usr/lang/SC2.0.1/values-Xt.o -L/usr/lang/SC2.0.1/cg87 -L/usr/lang/SC2.0.1
2553 and you need to add -lansi just before -lc.
2555 The precise file names depend on the compiler version, so we
2556 cannot easily arrange to supply them.
2558 *** Linking says that the functions insque and remque are undefined.
2560 Change oldXMenu/Makefile by adding insque.o to the variable OBJS.
2562 *** `tparam' reported as a multiply-defined symbol when linking with ncurses.
2564 This problem results from an incompatible change in ncurses, in
2565 version 1.9.9e approximately. This version is unable to provide a
2566 definition of tparm without also defining tparam. This is also
2567 incompatible with Terminfo; as a result, the Emacs Terminfo support
2568 does not work with this version of ncurses.
2570 The fix is to install a newer version of ncurses, such as version 4.2.
2574 Bootstrapping (compiling the .el files) is normally only necessary
2575 with development builds, since the .elc files are pre-compiled in releases.
2577 *** "No rule to make target" with Ubuntu 8.04 make 3.81-3build1
2579 Compiling the lisp files fails at random places, complaining:
2580 "No rule to make target `/path/to/some/lisp.elc'".
2581 The causes of this problem are not understood. Using GNU make 3.81 compiled
2582 from source, rather than the Ubuntu version, worked. See Bug#327,821.
2586 *** Linux: Segfault during `make bootstrap' under certain recent versions of the Linux kernel.
2588 With certain recent Linux kernels (like the one of Red Hat Fedora Core
2589 1 and newer), the new "Exec-shield" functionality is enabled by default, which
2590 creates a different memory layout that breaks the emacs dumper. Emacs tries
2591 to handle this at build time, but if the workaround used fails, these
2592 instructions can be useful.
2593 The work-around explained here is not enough on Fedora Core 4 (and possible
2594 newer). Read the next item.
2596 Configure can overcome the problem of exec-shield if the architecture is
2597 x86 and the program setarch is present. On other architectures no
2598 workaround is known.
2600 You can check the Exec-shield state like this:
2602 cat /proc/sys/kernel/exec-shield
2604 It returns non-zero when Exec-shield is enabled, 0 otherwise. Please
2605 read your system documentation for more details on Exec-shield and
2606 associated commands. Exec-shield can be turned off with this command:
2608 echo "0" > /proc/sys/kernel/exec-shield
2610 When Exec-shield is enabled, building Emacs will segfault during the
2611 execution of this command:
2613 ./temacs --batch --load loadup [dump|bootstrap]
2615 To work around this problem, it is necessary to temporarily disable
2616 Exec-shield while building Emacs, or, on x86, by using the `setarch'
2617 command when running temacs like this:
2619 setarch i386 ./temacs --batch --load loadup [dump|bootstrap]
2622 *** Fedora Core 4 GNU/Linux: Segfault during dumping.
2624 In addition to exec-shield explained above "Linux: Segfault during
2625 `make bootstrap' under certain recent versions of the Linux kernel"
2626 item, Linux kernel shipped with Fedora Core 4 randomizes the virtual
2627 address space of a process. As the result dumping may fail even if
2628 you turn off exec-shield. In this case, use the -R option to the setarch
2631 setarch i386 -R ./temacs --batch --load loadup [dump|bootstrap]
2635 setarch i386 -R make bootstrap
2637 *** Fatal signal in the command temacs -l loadup inc dump.
2639 This command is the final stage of building Emacs. It is run by the
2640 Makefile in the src subdirectory.
2642 It has been known to get fatal errors due to insufficient swapping
2643 space available on the machine.
2645 On 68000s, it has also happened because of bugs in the
2646 subroutine `alloca'. Verify that `alloca' works right, even
2647 for large blocks (many pages).
2649 *** test-distrib says that the distribution has been clobbered.
2650 *** or, temacs prints "Command key out of range 0-127".
2651 *** or, temacs runs and dumps emacs, but emacs totally fails to work.
2652 *** or, temacs gets errors dumping emacs.
2654 This can be because the .elc files have been garbled. Do not be
2655 fooled by the fact that most of a .elc file is text: these are
2656 binary files and can contain all 256 byte values.
2658 In particular `shar' cannot be used for transmitting GNU Emacs.
2659 It typically truncates "lines". What appear to be "lines" in
2660 a binary file can of course be of any length. Even once `shar'
2661 itself is made to work correctly, `sh' discards null characters
2662 when unpacking the shell archive.
2664 I have also seen character \177 changed into \377. I do not know
2665 what transfer means caused this problem. Various network
2666 file transfer programs are suspected of clobbering the high bit.
2668 If you have a copy of Emacs that has been damaged in its
2669 nonprinting characters, you can fix them:
2671 1) Record the names of all the .elc files.
2672 2) Delete all the .elc files.
2673 3) Recompile alloc.c with a value of PURESIZE twice as large.
2674 (See puresize.h.) You might as well save the old alloc.o.
2675 4) Remake emacs. It should work now.
2676 5) Running emacs, do Meta-x byte-compile-file repeatedly
2677 to recreate all the .elc files that used to exist.
2678 You may need to increase the value of the variable
2679 max-lisp-eval-depth to succeed in running the compiler interpreted
2680 on certain .el files. 400 was sufficient as of last report.
2681 6) Reinstall the old alloc.o (undoing changes to alloc.c if any)
2683 7) Remake emacs. It should work now, with valid .elc files.
2685 *** temacs prints "Pure Lisp storage exhausted".
2687 This means that the Lisp code loaded from the .elc and .el files
2688 during temacs -l loadup inc dump took up more space than was allocated.
2690 This could be caused by
2691 1) adding code to the preloaded Lisp files
2692 2) adding more preloaded files in loadup.el
2693 3) having a site-init.el or site-load.el which loads files.
2694 Note that ANY site-init.el or site-load.el is nonstandard;
2695 if you have received Emacs from some other site and it contains a
2696 site-init.el or site-load.el file, consider deleting that file.
2697 4) getting the wrong .el or .elc files
2698 (not from the directory you expected).
2699 5) deleting some .elc files that are supposed to exist.
2700 This would cause the source files (.el files) to be
2701 loaded instead. They take up more room, so you lose.
2702 6) a bug in the Emacs distribution which underestimates the space required.
2704 If the need for more space is legitimate, change the definition
2705 of PURESIZE in puresize.h.
2707 But in some of the cases listed above, this problem is a consequence
2708 of something else that is wrong. Be sure to check and fix the real problem.
2710 *** OpenBSD 4.0 macppc: Segfault during dumping.
2712 The build aborts with signal 11 when the command `./temacs --batch
2713 --load loadup bootstrap' tries to load files.el. A workaround seems
2714 to be to reduce the level of compiler optimization used during the
2715 build (from -O2 to -O1). It is possible this is an OpenBSD
2716 GCC problem specific to the macppc architecture, possibly only
2717 occurring with older versions of GCC (e.g. 3.3.5).
2719 *** openSUSE 10.3: Segfault in bcopy during dumping.
2721 This is due to a bug in the bcopy implementation in openSUSE 10.3.
2722 It is/will be fixed in an openSUSE update.
2726 *** Installing Emacs gets an error running `install-info'.
2728 You need to install a recent version of Texinfo; that package
2729 supplies the `install-info' command.
2731 *** Installing to a directory with spaces in the name fails.
2733 For example, if you call configure with a directory-related option
2734 with spaces in the value, eg --enable-locallisppath='/path/with\ spaces'.
2735 Using directory paths with spaces is not supported at this time: you
2736 must re-configure without using spaces.
2738 *** Installing to a directory with non-ASCII characters in the name fails.
2740 Installation may fail, or the Emacs executable may not start
2741 correctly, if a directory name containing non-ASCII characters is used
2742 as a `configure' argument (e.g. `--prefix'). The problem can also
2743 occur if a non-ASCII directory is specified in the EMACSLOADPATH
2746 *** On Solaris, use GNU Make when installing an out-of-tree build
2748 The Emacs configuration process allows you to configure the
2749 build environment so that you can build emacs in a directory
2750 outside of the distribution tree. When installing Emacs from an
2751 out-of-tree build directory on Solaris, you may need to use GNU
2752 make. The make programs bundled with Solaris support the VPATH
2753 macro but use it differently from the way the VPATH macro is
2754 used by GNU make. The differences will cause the "make install"
2755 step to fail, leaving you with an incomplete emacs
2756 installation. GNU make is available in /usr/sfw/bin on Solaris
2757 10 and can be installed as /opt/sfw/bin/gmake from the Solaris 9
2758 Software Companion CDROM.
2760 The problems due to the VPATH processing differences affect only
2761 out of tree builds so, if you are on a Solaris installation
2762 without GNU make, you can install Emacs completely by installing
2763 from a build environment using the original emacs distribution tree.
2767 *** Emacs binary is not in executable format, and cannot be run.
2769 This was reported to happen when Emacs is built in a directory mounted
2770 via NFS, for some combinations of NFS client and NFS server.
2771 Usually, the file `emacs' produced in these cases is full of
2772 binary null characters, and the `file' utility says:
2774 emacs: ASCII text, with no line terminators
2776 We don't know what exactly causes this failure. A work-around is to
2777 build Emacs in a directory on a local disk.
2779 *** The dumped Emacs crashes when run, trying to write pure data.
2781 Two causes have been seen for such problems.
2783 1) On a system where getpagesize is not a system call, it is defined
2784 as a macro. If the definition (in both unex*.c and malloc.c) is wrong,
2785 it can cause problems like this. You might be able to find the correct
2786 value in the man page for a.out (5).
2788 2) Some systems allocate variables declared static among the
2789 initialized variables. Emacs makes all initialized variables in most
2790 of its files pure after dumping, but the variables declared static and
2791 not initialized are not supposed to be pure. On these systems you
2792 may need to add "#define static" to config.h.
2794 * Runtime problems on legacy systems
2796 This section covers bugs reported on very old hardware or software.
2797 If you are using hardware and an operating system shipped after 2000,
2798 it is unlikely you will see any of these.
2800 *** OPENSTEP 4.2: Compiling syntax.c with gcc 2.7.2.1 fails.
2802 The compiler was reported to crash while compiling syntax.c with the
2805 cc: Internal compiler error: program cc1obj got fatal signal 11
2807 To work around this, replace the macros UPDATE_SYNTAX_TABLE_FORWARD,
2808 INC_BOTH, and INC_FROM with functions. To this end, first define 3
2809 functions, one each for every macro. Here's an example:
2811 static int update_syntax_table_forward(int from)
2813 return(UPDATE_SYNTAX_TABLE_FORWARD(from));
2814 }/*update_syntax_table_forward*/
2816 Then replace all references to UPDATE_SYNTAX_TABLE_FORWARD in syntax.c
2817 with a call to the function update_syntax_table_forward.
2821 **** Strange results from format %d in a few cases, on a Sun.
2823 Sun compiler version SC3.0 has been found to miscompile part of
2824 editfns.c. The workaround is to compile with some other compiler such
2827 **** On Solaris, Emacs dumps core if lisp-complete-symbol is called.
2829 If you compile Emacs with the -fast or -xO4 option with version 3.0.2
2830 of the Sun C compiler, Emacs dumps core when lisp-complete-symbol is
2831 called. The problem does not happen if you compile with GCC.
2833 **** On Solaris, Emacs crashes if you use (display-time).
2835 This can happen if you configure Emacs without specifying the precise
2836 version of Solaris that you are using.
2838 **** Solaris 2.x: GCC complains "64 bit integer types not supported".
2840 This suggests that GCC is not installed correctly. Most likely you
2841 are using GCC 2.7.2.3 (or earlier) on Solaris 2.6 (or later); this
2842 does not work without patching. To run GCC 2.7.2.3 on Solaris 2.6 or
2843 later, you must patch fixinc.svr4 and reinstall GCC from scratch as
2844 described in the Solaris FAQ
2845 <http://www.wins.uva.nl/pub/solaris/solaris2.html>. A better fix is
2846 to upgrade to GCC 2.8.1 or later.
2848 **** Solaris 2.7: Building Emacs with WorkShop Compilers 5.0 98/12/15
2849 C 5.0 failed, apparently with non-default CFLAGS, most probably due to
2850 compiler bugs. Using Sun Solaris 2.7 Sun WorkShop 6 update 1 C
2851 release was reported to work without problems. It worked OK on
2852 another system with Solaris 8 using apparently the same 5.0 compiler
2853 and the default CFLAGS.
2855 **** Solaris 2.x: Emacs dumps core when built with Motif.
2857 The Solaris Motif libraries are buggy, at least up through Solaris 2.5.1.
2858 Install the current Motif runtime library patch appropriate for your host.
2859 (Make sure the patch is current; some older patch versions still have the bug.)
2860 You should install the other patches recommended by Sun for your host, too.
2861 You can obtain Sun patches from ftp://sunsolve.sun.com/pub/patches/;
2862 look for files with names ending in `.PatchReport' to see which patches
2863 are currently recommended for your host.
2865 On Solaris 2.6, Emacs is said to work with Motif when Solaris patch
2866 105284-12 is installed, but fail when 105284-15 is installed.
2867 105284-18 might fix it again.
2869 **** Solaris 2.6 and 7: the Compose key does not work.
2871 This is a bug in Motif in Solaris. Supposedly it has been fixed for
2872 the next major release of Solaris. However, if someone with Sun
2873 support complains to Sun about the bug, they may release a patch.
2874 If you do this, mention Sun bug #4188711.
2876 One workaround is to use a locale that allows non-ASCII characters.
2877 For example, before invoking emacs, set the LC_ALL environment
2878 variable to "en_US" (American English). The directory /usr/lib/locale
2879 lists the supported locales; any locale other than "C" or "POSIX"
2882 pen@lysator.liu.se says (Feb 1998) that the Compose key does work
2883 if you link with the MIT X11 libraries instead of the Solaris X11 libraries.
2885 *** HP/UX 10: Large file support is disabled.
2886 (HP/UX 10 was end-of-lifed in May 1999.)
2887 See the comments in src/s/hpux10-20.h.
2889 *** HP/UX: Emacs is slow using X11R5.
2891 This happens if you use the MIT versions of the X libraries--it
2892 doesn't run as fast as HP's version. People sometimes use the version
2893 because they see the HP version doesn't have the libraries libXaw.a,
2894 libXmu.a, libXext.a and others. HP/UX normally doesn't come with
2895 those libraries installed. To get good performance, you need to
2896 install them and rebuild Emacs.
2898 *** UnixWare 2.1: Error 12 (virtual memory exceeded) when dumping Emacs.
2900 Paul Abrahams (abrahams@acm.org) reports that with the installed
2901 virtual memory settings for UnixWare 2.1.2, an Error 12 occurs during
2902 the "make" that builds Emacs, when running temacs to dump emacs. That
2903 error indicates that the per-process virtual memory limit has been
2904 exceeded. The default limit is probably 32MB. Raising the virtual
2905 memory limit to 40MB should make it possible to finish building Emacs.
2907 You can do this with the command `ulimit' (sh) or `limit' (csh).
2908 But you have to be root to do it.
2910 According to Martin Sohnius, you can also retune this in the kernel:
2912 # /etc/conf/bin/idtune SDATLIM 33554432 ## soft data size limit
2913 # /etc/conf/bin/idtune HDATLIM 33554432 ## hard "
2914 # /etc/conf/bin/idtune SVMMSIZE unlimited ## soft process size limit
2915 # /etc/conf/bin/idtune HVMMSIZE unlimited ## hard "
2916 # /etc/conf/bin/idbuild -B
2918 (He recommends you not change the stack limit, though.)
2919 These changes take effect when you reboot.
2921 ** MS-Windows 95, 98, ME, and NT
2923 *** MS-Windows NT/95: Problems running Perl under Emacs
2925 `perl -de 0' just hangs when executed in an Emacs subshell.
2926 The fault lies with Perl (indirectly with Windows NT/95).
2928 The problem is that the Perl debugger explicitly opens a connection to
2929 "CON", which is the DOS/NT equivalent of "/dev/tty", for interacting
2932 On Unix, this is okay, because Emacs (or the shell?) creates a
2933 pseudo-tty so that /dev/tty is really the pipe Emacs is using to
2934 communicate with the subprocess.
2936 On NT, this fails because CON always refers to the handle for the
2937 relevant console (approximately equivalent to a tty), and cannot be
2938 redirected to refer to the pipe Emacs assigned to the subprocess as
2941 A workaround is to modify perldb.pl to use STDIN/STDOUT instead of CON.
2945 *** PERL/LIB/PERLDB.PL.orig Wed May 26 08:24:18 1993
2946 --- PERL/LIB/PERLDB.PL Mon Jul 01 15:28:16 1996
2953 $rcfile="perldb.ini";
2961 $rcfile="perldb.ini";
2966 *** perl/5.001/lib/perl5db.pl.orig Sun Jun 04 21:13:40 1995
2967 --- perl/5.001/lib/perl5db.pl Mon Jul 01 17:00:08 1996
2974 $rcfile="perldb.ini";
2982 $rcfile="perldb.ini";
2986 *** MS-Windows 95: Alt-f6 does not get through to Emacs.
2988 This character seems to be trapped by the kernel in Windows 95.
2989 You can enter M-f6 by typing ESC f6.
2991 *** MS-Windows 95/98/ME: subprocesses do not terminate properly.
2993 This is a limitation of the Operating System, and can cause problems
2994 when shutting down Windows. Ensure that all subprocesses are exited
2995 cleanly before exiting Emacs. For more details, see the FAQ at
2996 http://www.gnu.org/software/emacs/windows/.
2998 *** MS-Windows 95/98/ME: crashes when Emacs invokes non-existent programs.
3000 When a program you are trying to run is not found on the PATH,
3001 Windows might respond by crashing or locking up your system. In
3002 particular, this has been reported when trying to compile a Java
3003 program in JDEE when javac.exe is installed, but not on the system PATH.
3007 *** When compiling with DJGPP on MS-Windows NT or later, "config msdos" fails.
3009 If the error message is "VDM has been already loaded", this is because
3010 Windows has a program called `redir.exe' that is incompatible with a
3011 program by the same name supplied with DJGPP, which is used by
3012 config.bat. To resolve this, move the DJGPP's `bin' subdirectory to
3013 the front of your PATH environment variable.
3015 *** When Emacs compiled with DJGPP runs on Windows 2000 and later, it cannot
3016 find your HOME directory.
3018 This was reported to happen when you click on "Save for future
3019 sessions" button in a Customize buffer. You might see an error
3020 message like this one:
3022 basic-save-buffer-2: c:/FOO/BAR/~dosuser/: no such directory
3024 (The telltale sign is the "~USER" part at the end of the directory
3025 Emacs complains about, where USER is your username or the literal
3026 string "dosuser", which is the default username set up by the DJGPP
3027 startup file DJGPP.ENV.)
3029 This happens when the functions `user-login-name' and
3030 `user-real-login-name' return different strings for your username as
3031 Emacs sees it. To correct this, make sure both USER and USERNAME
3032 environment variables are set to the same value. Windows 2000 and
3033 later sets USERNAME, so if you want to keep that, make sure USER is
3034 set to the same value. If you don't want to set USER globally, you
3035 can do it in the [emacs] section of your DJGPP.ENV file.
3037 *** When Emacs compiled with DJGPP runs on Vista, it runs out of memory.
3039 If Emacs running on Vista displays "!MEM FULL!" in the mode line, you
3040 are hitting the memory allocation bugs in the Vista DPMI server. See
3041 msdos/INSTALL for how to work around these bugs (search for "Vista").
3043 *** When compiling with DJGPP on MS-Windows 95, Make fails for some targets
3046 This can happen if long file name support (the setting of environment
3047 variable LFN) when Emacs distribution was unpacked and during
3048 compilation are not the same. See msdos/INSTALL for the explanation
3049 of how to avoid this problem.
3051 *** Emacs compiled with DJGPP complains at startup:
3053 "Wrong type of argument: internal-facep, msdos-menu-active-face"
3055 This can happen if you define an environment variable `TERM'. Emacs
3056 on MSDOS uses an internal terminal emulator which is disabled if the
3057 value of `TERM' is anything but the string "internal". Emacs then
3058 works as if its terminal were a dumb glass teletype that doesn't
3059 support faces. To work around this, arrange for `TERM' to be
3060 undefined when Emacs runs. The best way to do that is to add an
3061 [emacs] section to the DJGPP.ENV file which defines an empty value for
3062 `TERM'; this way, only Emacs gets the empty value, while the rest of
3063 your system works as before.
3065 *** MS-DOS: Emacs crashes at startup.
3067 Some users report that Emacs 19.29 requires dpmi memory management,
3068 and crashes on startup if the system does not have it. We don't
3069 know why this happens--perhaps these machines don't have enough real
3070 memory, or perhaps something is wrong in Emacs or the compiler.
3071 However, arranging to use dpmi support is a workaround.
3073 You can find out if you have a dpmi host by running go32 without
3074 arguments; it will tell you if it uses dpmi memory. For more
3075 information about dpmi memory, consult the djgpp FAQ. (djgpp
3076 is the GNU C compiler as packaged for MSDOS.)
3078 Compiling Emacs under MSDOS is extremely sensitive for proper memory
3079 configuration. If you experience problems during compilation, consider
3080 removing some or all memory resident programs (notably disk caches)
3081 and make sure that your memory managers are properly configured. See
3082 the djgpp faq for configuration hints.
3084 *** Emacs compiled with DJGPP for MS-DOS/MS-Windows cannot access files
3085 in the directory with the special name `dev' under the root of any
3086 drive, e.g. `c:/dev'.
3088 This is an unfortunate side-effect of the support for Unix-style
3089 device names such as /dev/null in the DJGPP runtime library. A
3090 work-around is to rename the problem directory to another name.
3092 *** MS-DOS+DJGPP: Problems on MS-DOS if DJGPP v2.0 is used to compile Emacs.
3094 There are two DJGPP library bugs which cause problems:
3096 * Running `shell-command' (or `compile', or `grep') you get
3097 `Searching for program: permission denied (EACCES), c:/command.com';
3098 * After you shell to DOS, Ctrl-Break kills Emacs.
3100 To work around these bugs, you can use two files in the msdos
3101 subdirectory: `is_exec.c' and `sigaction.c'. Compile them and link
3102 them into the Emacs executable `temacs'; then they will replace the
3103 incorrect library functions.
3105 *** MS-DOS: Emacs compiled for MSDOS cannot find some Lisp files, or other
3106 run-time support files, when long filename support is enabled.
3108 Usually, this problem will manifest itself when Emacs exits
3109 immediately after flashing the startup screen, because it cannot find
3110 the Lisp files it needs to load at startup. Redirect Emacs stdout
3111 and stderr to a file to see the error message printed by Emacs.
3113 Another manifestation of this problem is that Emacs is unable to load
3114 the support for editing program sources in languages such as C and Lisp.
3116 This can happen if the Emacs distribution was unzipped without LFN
3117 support, thus causing long filenames to be truncated to the first 6
3118 characters and a numeric tail that Windows 95 normally attaches to it.
3119 You should unzip the files again with a utility that supports long
3120 filenames (such as djtar from DJGPP or InfoZip's UnZip program
3121 compiled with DJGPP v2). The file msdos/INSTALL explains this issue
3124 Another possible reason for such failures is that Emacs compiled for
3125 MSDOS is used on Windows NT, where long file names are not supported
3126 by this version of Emacs, but the distribution was unpacked by an
3127 unzip program that preserved the long file names instead of truncating
3128 them to DOS 8+3 limits. To be useful on NT, the MSDOS port of Emacs
3129 must be unzipped by a DOS utility, so that long file names are
3132 ** Archaic window managers and toolkits
3134 *** OpenLook: Under OpenLook, the Emacs window disappears when you type M-q.
3136 Some versions of the Open Look window manager interpret M-q as a quit
3137 command for whatever window you are typing at. If you want to use
3138 Emacs with that window manager, you should try to configure the window
3139 manager to use some other command. You can disable the
3140 shortcut keys entirely by adding this line to ~/.OWdefaults:
3142 OpenWindows.WindowMenuAccelerators: False
3144 *** twm: A position you specified in .Xdefaults is ignored, using twm.
3146 twm normally ignores "program-specified" positions.
3147 You can tell it to obey them with this command in your `.twmrc' file:
3149 UsePPosition "on" #allow clients to request a position
3151 ** Bugs related to old DEC hardware
3153 *** The Compose key on a DEC keyboard does not work as Meta key.
3155 This shell command should fix it:
3157 xmodmap -e 'keycode 0xb1 = Meta_L'
3159 *** Keyboard input gets confused after a beep when using a DECserver
3162 This problem seems to be a matter of configuring the DECserver to use
3163 7 bit characters rather than 8 bit characters.
3165 * Build problems on legacy systems
3167 ** SunOS: Emacs gets error message from linker on Sun.
3169 If the error message says that a symbol such as `f68881_used' or
3170 `ffpa_used' or `start_float' is undefined, this probably indicates
3171 that you have compiled some libraries, such as the X libraries,
3172 with a floating point option other than the default.
3174 It's not terribly hard to make this work with small changes in
3175 crt0.c together with linking with Fcrt1.o, Wcrt1.o or Mcrt1.o.
3176 However, the easiest approach is to build Xlib with the default
3177 floating point option: -fsoft.
3179 ** HPUX 10.20: Emacs crashes during dumping on the HPPA machine.
3181 This seems to be due to a GCC bug; it is fixed in GCC 2.8.1.
3183 ** Vax C compiler bugs affecting Emacs.
3185 You may get one of these problems compiling Emacs:
3187 foo.c line nnn: compiler error: no table entry for op STASG
3188 foo.c: fatal error in /lib/ccom
3190 These are due to bugs in the C compiler; the code is valid C.
3191 Unfortunately, the bugs are unpredictable: the same construct
3192 may compile properly or trigger one of these bugs, depending
3193 on what else is in the source file being compiled. Even changes
3194 in header files that should not affect the file being compiled
3195 can affect whether the bug happens. In addition, sometimes files
3196 that compile correctly on one machine get this bug on another machine.
3198 As a result, it is hard for me to make sure this bug will not affect
3199 you. I have attempted to find and alter these constructs, but more
3200 can always appear. However, I can tell you how to deal with it if it
3201 should happen. The bug comes from having an indexed reference to an
3202 array of Lisp_Objects, as an argument in a function call:
3205 ... foo (5, args[i], ...)...
3206 putting the argument into a temporary variable first, as in
3211 ... foo (r, tem, ...)...
3212 causes the problem to go away.
3213 The `contents' field of a Lisp vector is an array of Lisp_Objects,
3214 so you may see the problem happening with indexed references to that.
3216 ** 68000 C compiler problems
3218 Various 68000 compilers have different problems.
3219 These are some that have been observed.
3221 *** Using value of assignment expression on union type loses.
3222 This means that x = y = z; or foo (x = z); does not work
3223 if x is of type Lisp_Object.
3225 *** "cannot reclaim" error.
3227 This means that an expression is too complicated. You get the correct
3228 line number in the error message. The code must be rewritten with
3229 simpler expressions.
3231 *** XCONS, XSTRING, etc macros produce incorrect code.
3233 If temacs fails to run at all, this may be the cause.
3234 Compile this test program and look at the assembler code:
3236 struct foo { char x; unsigned int y : 24; };
3241 test ((int *) arg.y);
3244 If the code is incorrect, your compiler has this problem.
3245 In the XCONS, etc., macros in lisp.h you must replace (a).u.val with
3246 ((a).u.val + coercedummy) where coercedummy is declared as int.
3248 This problem will only happen if USE_LISP_UNION_TYPE is manually
3251 ** C compilers lose on returning unions.
3253 I hear that some C compilers cannot handle returning a union type.
3254 Most of the functions in GNU Emacs return type Lisp_Object, which is
3255 defined as a union on some rare architectures.
3257 This problem will only happen if USE_LISP_UNION_TYPE is manually
3261 This file is part of GNU Emacs.
3263 GNU Emacs is free software: you can redistribute it and/or modify
3264 it under the terms of the GNU General Public License as published by
3265 the Free Software Foundation, either version 3 of the License, or
3266 (at your option) any later version.
3268 GNU Emacs is distributed in the hope that it will be useful,
3269 but WITHOUT ANY WARRANTY; without even the implied warranty of
3270 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3271 GNU General Public License for more details.
3273 You should have received a copy of the GNU General Public License
3274 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
3279 paragraph-separate: "[
\f]*$"