1 Known Problems with GNU Emacs
3 Copyright (C) 1987-1989, 1993-1999, 2001-2017 Free Software Foundation,
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 onwards
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 are:
30 - in the X server resources database, often initialized from
31 ~/.Xresources (use $ xrdb -query to find out the current state)
33 - in your ~/.Xdefaults file
35 - client-side X resource file, such as ~/Emacs or
36 /usr/share/X11/app-defaults/Emacs
38 One of these files might have bad or malformed specification of a
39 fontset that Emacs should use. To fix the problem, you need to find
40 the problematic line(s) and correct them.
42 After correcting ~/.Xresources, the new data has to be merged into the
43 X server resources database. Depending on the circumstances, the
44 following command may do the trick. See xrdb(1) for more information.
46 $ xrdb -merge ~/.Xresources
48 ** Emacs aborts while starting up, only when run without X.
50 This problem often results from compiling Emacs with GCC when GCC was
51 installed incorrectly. The usual error in installing GCC is to
52 specify --includedir=/usr/include. Installation of GCC makes
53 corrected copies of the system header files. GCC is supposed to use
54 the corrected copies in preference to the original system headers.
55 Specifying --includedir=/usr/include causes the original system header
56 files to be used. On some systems, the definition of ioctl in the
57 original system header files is invalid for ANSI C and causes Emacs
60 The fix is to reinstall GCC, and this time do not specify --includedir
61 when you configure it. Then recompile Emacs. Specifying --includedir
62 is appropriate only in very special cases and it should *never* be the
63 same directory where system header files are kept.
65 ** Emacs does not start, complaining that it cannot open termcap database file.
67 If your system uses Terminfo rather than termcap (most modern
68 systems do), this could happen if the proper version of
69 ncurses is not visible to the Emacs configure script (i.e. it
70 cannot be found along the usual path the linker looks for
71 libraries). It can happen because your version of ncurses is
72 obsolete, or is available only in form of binaries.
74 The solution is to install an up-to-date version of ncurses in
75 the developer's form (header files, static libraries and
76 symbolic links); in some GNU/Linux distributions (e.g. Debian)
77 it constitutes a separate package.
79 ** Emacs 20 and later fails to load Lisp files at startup.
81 The typical error message might be like this:
83 "Cannot open load file: fontset"
85 This could happen if you compress the file lisp/subdirs.el. That file
86 tells Emacs what are the directories where it should look for Lisp
87 files. Emacs cannot work with subdirs.el compressed, since the
88 Auto-compress mode it needs for this will not be loaded until later,
89 when your .emacs file is processed. (The package 'fontset.el' is
90 required to set up fonts used to display text on window systems, and
91 it's loaded very early in the startup procedure.)
93 Similarly, any other .el file for which there's no corresponding .elc
94 file could fail to load if it is compressed.
96 The solution is to uncompress all .el files that don't have a .elc file.
98 Another possible reason for such failures is stale *.elc files
99 lurking somewhere on your load-path -- see the next section.
101 ** Emacs prints an error at startup after upgrading from an earlier version.
103 An example of such an error is:
105 x-complement-fontset-spec: "Wrong type argument: stringp, nil"
107 This can be another symptom of stale *.elc files in your load-path.
108 The following command will print any duplicate Lisp files that are
109 present in load-path:
111 emacs -batch -f list-load-path-shadows
113 If this command prints any file names, some of these files are stale,
114 and should be deleted or their directories removed from your
119 ** Emacs crashes when running in a terminal, if compiled with GCC 4.5.0
121 This version of GCC is buggy: see
123 http://debbugs.gnu.org/6031
124 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43904
126 You can work around this error in gcc-4.5 by omitting sibling call
127 optimization. To do this, configure Emacs with
129 CFLAGS="-g -O2 -fno-optimize-sibling-calls" ./configure
131 ** Emacs compiled with GCC 4.6.1 crashes on MS-Windows when C-g is pressed
133 This is known to happen when Emacs is compiled with MinGW GCC 4.6.1
134 with the -O2 option (which is the default in the Windows build). The
135 reason is a bug in MinGW GCC 4.6.1; to work around, either add the
136 '-fno-omit-frame-pointer' switch to GCC or compile without
137 optimizations ('--no-opt' switch to the configure.bat script).
139 ** Emacs crashes in x-popup-dialog.
141 This can happen if the dialog widget cannot find the font it wants to
142 use. You can work around the problem by specifying another font with
143 an X resource--for example, 'Emacs.dialog*.font: 9x15' (or any font that
144 happens to exist on your X server).
146 ** Emacs crashes when you use Bibtex mode.
148 This happens if your system puts a small limit on stack size. You can
149 prevent the problem by using a suitable shell command (often 'ulimit')
150 to raise the stack size limit before you run Emacs.
152 Patches to raise the stack size limit automatically in 'main'
153 (src/emacs.c) on various systems would be greatly appreciated.
155 ** Error message 'Symbol’s value as variable is void: x', followed by
156 a segmentation fault and core dump.
158 This has been tracked to a bug in tar! People report that tar erroneously
159 added a line like this at the beginning of files of Lisp code:
161 x FILENAME, N bytes, B tape blocks
163 If your tar has this problem, install GNU tar--if you can manage to
166 ** Emacs can crash when displaying PNG images with transparency.
168 This is due to a bug introduced in ImageMagick 6.8.2-3. The bug should
169 be fixed in ImageMagick 6.8.3-10. See <URL:http://debbugs.gnu.org/13867>.
171 ** Crashes when displaying GIF images in Emacs built with version
172 libungif-4.1.0 are resolved by using version libungif-4.1.0b1.
173 Configure checks for the correct version, but this problem could occur
174 if a binary built against a shared libungif is run on a system with an
177 ** Emacs aborts inside the function 'tparam1'.
179 This can happen if Emacs was built without terminfo support, but the
180 terminal's capabilities use format that is only supported by terminfo.
181 If your system has ncurses installed, this might happen if your
182 version of ncurses is broken; upgrading to a newer version of ncurses
183 and reconfiguring and rebuilding Emacs should solve this.
185 All modern systems support terminfo, so even if ncurses is not the
186 problem, you should look for a way to configure Emacs so that it uses
189 ** Emacs crashes when using some version of the Exceed X server.
191 Upgrading to a newer version of Exceed has been reported to prevent
192 these crashes. You should consider switching to a free X server, such
193 as Xming or Cygwin/X.
195 ** Emacs crashes with SIGSEGV in XtInitializeWidgetClass.
197 It crashes on X, but runs fine when called with option "-nw".
199 This has been observed when Emacs is linked with GNU ld but without passing
200 the -z nocombreloc flag. Emacs normally knows to pass the -z nocombreloc
201 flag when needed, so if you come across a situation where the flag is
202 necessary but missing, please report it via M-x report-emacs-bug.
204 On platforms such as Solaris, you can also work around this problem by
205 configuring your compiler to use the native linker instead of GNU ld.
207 ** When Emacs is compiled with Gtk+, closing a display kills Emacs.
209 There is a long-standing bug in GTK that prevents it from recovering
210 from disconnects: http://bugzilla.gnome.org/show_bug.cgi?id=85715.
212 Thus, for instance, when Emacs is run as a server on a text terminal,
213 and an X frame is created, and the X server for that frame crashes or
214 exits unexpectedly, Emacs must exit to prevent a GTK error that would
215 result in an endless loop.
217 If you need Emacs to be able to recover from closing displays, compile
218 it with the Lucid toolkit instead of GTK.
220 ** Emacs crashes when you try to view a file with complex characters.
222 For example, the etc/HELLO file (as shown by C-h h).
223 The message "symbol lookup error: /usr/bin/emacs: undefined symbol: OTF_open"
224 is shown in the terminal from which you launched Emacs.
225 This problem only happens when you use a graphical display (ie not
226 with -nw) and compiled Emacs with the "libotf" library for complex
229 This problem occurs because unfortunately there are two libraries
230 called "libotf". One is the library for handling OpenType fonts,
231 http://www.m17n.org/libotf/, which is the one that Emacs expects.
232 The other is a library for Open Trace Format, and is used by some
233 versions of the MPI message passing interface for parallel
236 For example, on RHEL6 GNU/Linux, the OpenMPI rpm provides a version
237 of "libotf.so" in /usr/lib/openmpi/lib. This directory is not
238 normally in the ld search path, but if you want to use OpenMPI,
239 you must issue the command "module load openmpi". This adds
240 /usr/lib/openmpi/lib to LD_LIBRARY_PATH. If you then start Emacs from
241 the same shell, you will encounter this crash.
242 Ref: <URL:https://bugzilla.redhat.com/show_bug.cgi?id=844776>
244 There is no good solution to this problem if you need to use both
245 OpenMPI and Emacs with libotf support. The best you can do is use a
246 wrapper shell script (or function) "emacs" that removes the offending
247 element from LD_LIBRARY_PATH before starting emacs proper.
248 Or you could recompile Emacs with an -Wl,-rpath option that
249 gives the location of the correct libotf.
251 * General runtime problems
255 *** Changes made to .el files do not take effect.
257 You may have forgotten to recompile them into .elc files.
258 Then the old .elc files will be loaded, and your changes
259 will not be seen. To fix this, do M-x byte-recompile-directory
260 and specify the directory that contains the Lisp files.
262 Emacs prints a warning when loading a .elc file which is older
263 than the corresponding .el file.
265 Alternatively, if you set the option 'load-prefer-newer' non-nil,
266 Emacs will load whichever version of a file is the newest.
268 *** Watch out for the EMACSLOADPATH environment variable
270 EMACSLOADPATH overrides which directories the function "load" will search.
272 If you observe strange problems, check for this variable in your
275 *** Using epop3.el package causes Emacs to signal an error.
277 The error message might be something like this:
279 "Lisp nesting exceeds max-lisp-eval-depth"
281 This happens because epop3 redefines the function gethash, which is a
282 built-in primitive beginning with Emacs 21.1. We don't have a patch
283 for epop3 to fix it, but perhaps a newer version of epop3 corrects that.
285 *** Buffers from 'with-output-to-temp-buffer' get set up in Help mode.
287 Changes in Emacs 20.4 to the hooks used by that function cause
288 problems for some packages, specifically BBDB. See the function's
289 documentation for the hooks involved. BBDB 2.00.06 fixes the problem.
291 *** The Hyperbole package causes *Help* buffers not to be displayed in
292 Help mode due to setting 'temp-buffer-show-hook' rather than using
293 'add-hook'. Using '(add-hook 'temp-buffer-show-hook 'help-mode-finish)'
294 after loading Hyperbole should fix this.
298 *** Unable to enter the M-| key on some German keyboards.
299 Some users have reported that M-| suffers from "keyboard ghosting".
300 This can't be fixed by Emacs, as the keypress never gets passed to it
301 at all (as can be verified using "xev"). You can work around this by
302 typing 'ESC |' instead.
304 *** "Compose Character" key does strange things when used as a Meta key.
306 If you define one key to serve as both Meta and Compose Character, you
307 will get strange results. In previous Emacs versions, this "worked"
308 in that the key acted as Meta--that's because the older Emacs versions
309 did not try to support Compose Character. Now Emacs tries to do
310 character composition in the standard X way. This means that you
311 must pick one meaning or the other for any given key.
313 You can use both functions (Meta, and Compose Character) if you assign
314 them to two different keys.
316 *** C-z just refreshes the screen instead of suspending Emacs.
318 You are probably using a shell that doesn't support job control, even
319 though the system itself is capable of it. Either use a different shell,
320 or set the variable 'cannot-suspend' to a non-nil value.
322 ** Mailers and other helper programs
324 *** movemail compiled with POP support can't connect to the POP server.
326 Make sure that the 'pop' entry in /etc/services, or in the services
327 NIS map if your machine uses NIS, has the same port number as the
328 entry on the POP server. A common error is for the POP server to be
329 listening on port 110, the assigned port for the POP3 protocol, while
330 the client is trying to connect on port 109, the assigned port for the
333 *** RMAIL gets error getting new mail.
335 RMAIL gets new mail from /usr/spool/mail/$USER using a program
336 called 'movemail'. This program interlocks with /bin/mail using
337 the protocol defined by /bin/mail.
339 There are two different protocols in general use. One of them uses
340 the 'flock' system call. The other involves creating a lock file;
341 'movemail' must be able to write in /usr/spool/mail in order to do
342 this. You control which one is used by defining, or not defining,
343 the macro MAIL_USE_FLOCK in config.h.
344 IF YOU DON'T USE THE FORM OF INTERLOCKING THAT IS NORMAL ON YOUR
345 SYSTEM, YOU CAN LOSE MAIL!
347 If your system uses the lock file protocol, and fascist restrictions
348 prevent ordinary users from writing the lock files in /usr/spool/mail,
349 you may need to make 'movemail' setgid to a suitable group such as
350 'mail'. To do this, use the following commands (as root) after doing the
356 Installation normally copies movemail from the build directory to an
357 installation directory which is usually under /usr/local/lib. The
358 installed copy of movemail is usually in the directory
359 /usr/local/lib/emacs/VERSION/TARGET. You must change the group and
360 mode of the installed copy; changing the group and mode of the build
361 directory copy is ineffective.
363 *** rcs2log gives you the awk error message "too many fields".
365 This is due to an arbitrary limit in certain versions of awk.
366 The solution is to use gawk (GNU awk).
368 ** Problems with hostname resolution
370 *** Emacs does not know your host's fully-qualified domain name.
372 For example, (system-name) returns some variation on
373 "localhost.localdomain", rather the name you were expecting.
375 You need to configure your machine with a fully qualified domain name,
376 (i.e., a name with at least one "."), either in /etc/hostname
377 or wherever your system calls for specifying this.
379 If you cannot fix the configuration, you can set the Lisp variable
380 mail-host-address to the value you want.
384 *** Emacs says it has saved a file, but the file does not actually
387 This can happen on certain systems when you are using NFS, if the
388 remote disk is full. It is due to a bug in NFS (or certain NFS
389 implementations), and there is apparently nothing Emacs can do to
390 detect the problem. Emacs checks the failure codes of all the system
391 calls involved in writing a file, including 'close'; but in the case
392 where the problem occurs, none of those system calls fails.
394 ** PSGML conflicts with sgml-mode.
396 PSGML package uses the same names of some variables (like keymap)
397 as built-in sgml-mode.el because it was created as a replacement
398 of that package. The conflict will be shown if you load
399 sgml-mode.el before psgml.el. E.g. this could happen if you edit
400 HTML page and then start to work with SGML or XML file. html-mode
401 (from sgml-mode.el) is used for HTML file and loading of psgml.el
402 (for sgml-mode or xml-mode) will cause an error.
406 *** Lines are not updated or new lines are added in the buffer upon commit.
408 When committing files located higher in the hierarchy than the examined
409 directory, some versions of the CVS program return an ambiguous message
410 from which PCL-CVS cannot extract the full location of the committed
411 files. As a result, the corresponding lines in the PCL-CVS buffer are
412 not updated with the new revision of these files, and new lines are
413 added to the top-level directory.
415 This can happen with CVS versions 1.12.8 and 1.12.9. Upgrade to CVS
416 1.12.10 or newer to fix this problem.
418 ** Miscellaneous problems
420 *** Editing files with very long lines is slow.
422 For example, simply moving through a file that contains hundreds of
423 thousands of characters per line is slow, and consumes a lot of CPU.
424 This is a known limitation of Emacs with no solution at this time.
426 *** Emacs uses 100% of CPU time
428 This was a known problem with some old versions of the Semantic package.
429 The solution was to upgrade Semantic to version 2.0pre4 (distributed
430 with CEDET 1.0pre4) or later. Note that Emacs includes Semantic since
431 23.2, and this issue does not apply to the included version.
433 *** Self-documentation messages are garbled.
435 This means that the file 'etc/DOC' doesn't properly correspond
436 with the Emacs executable. Redumping Emacs and then installing the
437 corresponding pair of files should fix the problem.
439 *** Programs running under terminal emulator do not recognize 'emacs'
442 The cause of this is a shell startup file that sets the TERMCAP
443 environment variable. The terminal emulator uses that variable to
444 provide the information on the special terminal type that Emacs emulates.
446 Rewrite your shell startup file so that it does not change TERMCAP
447 in such a case. You could use the following conditional which sets
448 it only if it is undefined.
450 if ( ! ${?TERMCAP} ) setenv TERMCAP ~/my-termcap-file
452 Or you could set TERMCAP only when you set TERM--which should not
453 happen in a non-login shell.
455 *** In Shell mode, you get a ^M at the end of every line.
457 This happens to people who use tcsh, because it is trying to be too
458 smart. It sees that the Shell uses terminal type 'unknown' and turns
459 on the flag to output ^M at the end of each line. You can fix the
460 problem by adding this to your .cshrc file:
462 if ($?INSIDE_EMACS && $?tcsh)
464 stty -icrnl -onlcr -echo susp ^Z
467 *** Emacs startup on GNU/Linux systems (and possibly other systems) is slow.
469 This can happen if the system is misconfigured and Emacs can't get the
470 full qualified domain name, FQDN. You should have your FQDN in the
471 /etc/hosts file, something like this:
474 129.187.137.82 nuc04.t30.physik.tu-muenchen.de nuc04
476 The way to set this up may vary on non-GNU systems.
478 *** Visiting files in some auto-mounted directories causes Emacs to print
479 'Error reading dir-locals: (file-error "Read error" "is a directory" ...'
481 This can happen if the auto-mounter mistakenly reports that
482 .dir-locals.el exists and is a directory. There is nothing Emacs can
483 do about this, but you can avoid the issue by adding a suitable entry
484 to the variable 'locate-dominating-stop-dir-regexp'. For example, if
485 the problem relates to "/smb/.dir-locals.el", set that variable
486 to a new value where you replace "net\\|afs" with "net\\|afs\\|smb".
487 (The default value already matches common auto-mount prefixes.)
488 See http://lists.gnu.org/archive/html/help-gnu-emacs/2015-02/msg00461.html .
490 *** Attempting to visit remote files via ange-ftp fails.
492 If the error message is "ange-ftp-file-modtime: Specified time is not
493 representable", then this could happen when 'lukemftp' is used as the
494 ftp client. This was reported to happen on Debian GNU/Linux, kernel
495 version 2.4.3, with 'lukemftp' 1.5-5, but might happen on other
496 systems as well. To avoid this problem, switch to using the standard
497 ftp client. On a Debian system, type
499 update-alternatives --config ftp
501 and then choose /usr/bin/netkit-ftp.
503 *** Dired is very slow.
505 This could happen if invocation of the 'df' program takes a long
506 time. Possible reasons for this include:
508 - ClearCase mounted filesystems (VOBs) that sometimes make 'df'
509 response time extremely slow (dozens of seconds);
511 - slow automounters on some old versions of Unix;
513 - slow operation of some versions of 'df'.
515 To work around the problem, you could either (a) set the variable
516 'directory-free-space-program' to nil, and thus prevent Emacs from
517 invoking 'df'; (b) use 'df' from the GNU Coreutils package; or
518 (c) use CVS, which is Free Software, instead of ClearCase.
520 *** ps-print commands fail to find prologue files ps-prin*.ps.
522 This can happen if you use an old version of X-Symbol package: it
523 defines compatibility functions which trick ps-print into thinking it
524 runs in XEmacs, and look for the prologue files in a wrong directory.
526 The solution is to upgrade X-Symbol to a later version.
528 *** On systems with shared libraries you might encounter run-time errors
529 from the dynamic linker telling you that it is unable to find some
530 shared libraries, for instance those for Xaw3d or image support.
531 These errors mean Emacs has been linked with a library whose shared
532 library is not in the default search path of the dynamic linker.
534 Similar problems could prevent Emacs from building, since the build
535 process invokes Emacs several times.
537 On many systems, it is possible to set LD_LIBRARY_PATH in your
538 environment to specify additional directories where shared libraries
541 Other systems allow to set LD_RUN_PATH in a similar way, but before
542 Emacs is linked. With LD_RUN_PATH set, the linker will include a
543 specified run-time search path in the executable.
545 Please refer to the documentation of your dynamic linker for details.
547 *** When you run Ispell from Emacs, it reports a "misalignment" error.
549 This can happen if you compiled the Ispell program to use ASCII
550 characters only and then try to use it from Emacs with non-ASCII
551 characters, like Latin-1. The solution is to recompile Ispell with
552 support for 8-bit characters.
554 To see whether your Ispell program supports 8-bit characters, type
555 this at your shell's prompt:
559 and look in the output for the string "NO8BIT". If Ispell says
560 "!NO8BIT (8BIT)", your speller supports 8-bit characters; otherwise it
563 To rebuild Ispell with 8-bit character support, edit the local.h file
564 in the Ispell distribution and make sure it does _not_ define NO8BIT.
565 Then rebuild the speller.
567 Another possible cause for "misalignment" error messages is that the
568 version of Ispell installed on your machine is old. Upgrade.
570 Yet another possibility is that you are trying to spell-check a word
571 in a language that doesn't fit the dictionary you choose for use by
572 Ispell. (Ispell can only spell-check one language at a time, because
573 it uses a single dictionary.) Make sure that the text you are
574 spelling and the dictionary used by Ispell conform to each other.
576 If your spell-checking program is Aspell, it has been reported that if
577 you have a personal configuration file (normally ~/.aspell.conf), it
578 can cause this error. Remove that file, execute 'ispell-kill-ispell'
579 in Emacs, and then try spell-checking again.
581 *** TLS problems, e.g., Gnus hangs when fetching via imaps
582 http://debbugs.gnu.org/24247
584 gnutls-cli 3.5.3 (2016-08-09) does not generate a "- Handshake was
585 completed" message that tls.el relies upon, causing affected Emacs
586 functions to hang. To work around the problem, use older or newer
587 versions of gnutls-cli, or use Emacs's built-in gnutls support.
589 * Runtime problems related to font handling
591 ** Characters are displayed as empty boxes or with wrong font under X.
593 *** This can occur when two different versions of FontConfig are used.
594 For example, XFree86 4.3.0 has one version and Gnome usually comes
595 with a newer version. Emacs compiled with Gtk+ will then use the
596 newer version. In most cases the problem can be temporarily fixed by
597 stopping the application that has the error (it can be Emacs or any
598 other application), removing ~/.fonts.cache-1, and then starting the
599 application again. If removing ~/.fonts.cache-1 and restarting
600 doesn't help, the application with problem must be recompiled with the
601 same version of FontConfig as the rest of the system uses. For KDE,
602 it is sufficient to recompile Qt.
604 *** Some fonts have a missing glyph and no default character. This is
605 known to occur for character number 160 (no-break space) in some
606 fonts, such as Lucida but Emacs sets the display table for the unibyte
607 and Latin-1 version of this character to display a space.
609 *** Some of the fonts called for in your fontset may not exist on your
612 Each X font covers just a fraction of the characters that Emacs
613 supports. To display the whole range of Emacs characters requires
614 many different fonts, collected into a fontset. You can remedy the
615 problem by installing additional fonts.
617 The intlfonts distribution includes a full spectrum of fonts that can
618 display all the characters Emacs supports. The etl-unicode collection
619 of fonts (available from <URL:ftp://ftp.x.org/contrib/fonts/>) includes
620 fonts that can display many Unicode characters; they can also be used
621 by ps-print and ps-mule to print Unicode characters.
623 ** Under X, some characters appear improperly aligned in their lines.
625 You may have bad fonts.
627 ** Under X, an unexpected monospace font is used as the default font.
629 When compiled with XFT, Emacs tries to use a default font named
630 "monospace". This is a "virtual font", which the operating system
631 (Fontconfig) redirects to a suitable font such as DejaVu Sans Mono.
632 On some systems, there exists a font that is actually named Monospace,
633 which takes over the virtual font. This is considered an operating
636 http://lists.gnu.org/archive/html/emacs-devel/2008-10/msg00696.html
638 If you encounter this problem, set the default font to a specific font
639 in your .Xresources or initialization file. For instance, you can put
640 the following in your .Xresources:
642 Emacs.font: DejaVu Sans Mono 12
644 ** Certain fonts make each line take one pixel more than it should.
646 This is because these fonts contain characters a little taller than
647 the font's nominal height. Emacs needs to make sure that lines do not
650 ** Font Lock displays portions of the buffer in incorrect faces.
652 By far the most frequent cause of this is a parenthesis '(' or a brace
653 '{' in column zero. Font Lock assumes that such a paren is outside of
654 any comment or string. This is of course not true in general, but the
655 vast majority of well-formatted program source files don't have such
656 parens, and therefore this assumption is used to allow optimizations
657 in Font Lock's syntactical analysis. These optimizations avoid some
658 pathological cases where jit-lock, the Just-in-Time fontification
659 introduced with Emacs 21.1, could significantly slow down scrolling
660 through the buffer, especially scrolling backwards, and also jumping
661 to the end of a very large buffer.
663 Beginning with version 22.1, a parenthesis or a brace in column zero
664 is highlighted in bold-red face if it is inside a string or a comment,
665 to indicate that it could interfere with Font Lock (and also with
666 indentation) and should be moved or escaped with a backslash.
668 If you don't use large buffers, or have a very fast machine which
669 makes the delays insignificant, you can avoid the incorrect
670 fontification by setting the variable
671 'font-lock-beginning-of-syntax-function' to a nil value. (This must
672 be done _after_ turning on Font Lock.)
674 Another alternative is to avoid a paren in column zero. For example,
675 in a Lisp string you could precede the paren with a backslash.
677 ** Emacs pauses for several seconds when changing the default font.
679 This has been reported for fvwm 2.2.5 and the window manager of KDE
680 2.1. The reason for the pause is Xt waiting for a ConfigureNotify
681 event from the window manager, which the window manager doesn't send.
682 Xt stops waiting after a default timeout of usually 5 seconds.
684 A workaround for this is to add something like
686 emacs.waitForWM: false
688 to your X resources. Alternatively, add '(wait-for-wm . nil)' to a
689 frame's parameter list, like this:
691 (modify-frame-parameters nil '((wait-for-wm . nil)))
693 (this should go into your '.emacs' file).
695 ** Underlines appear at the wrong position.
697 This is caused by fonts having a wrong UNDERLINE_POSITION property.
698 Examples are the 7x13 font on XFree86 prior to version 4.1, or the jmk
699 neep font from the Debian xfonts-jmk package prior to version 3.0.17.
700 To circumvent this problem, set x-use-underline-position-properties
701 to nil in your '.emacs'.
703 To see what is the value of UNDERLINE_POSITION defined by the font,
704 type 'xlsfonts -lll FONT' and look at the font's UNDERLINE_POSITION property.
706 ** When using Exceed, fonts sometimes appear too tall.
708 When the display is set to an Exceed X-server and fonts are specified
709 (either explicitly with the -fn option or implicitly with X resources)
710 then the fonts may appear "too tall". The actual character sizes are
711 correct but there is too much vertical spacing between rows, which
712 gives the appearance of "double spacing".
714 To prevent this, turn off the Exceed's "automatic font substitution"
715 feature (in the font part of the configuration window).
717 ** Subscript/superscript text in TeX is hard to read.
719 If 'tex-fontify-script' is non-nil, tex-mode displays
720 subscript/superscript text in the faces subscript/superscript, which
721 are smaller than the normal font and lowered/raised. With some fonts,
722 nested superscripts (say) can be hard to read. Switching to a
723 different font, or changing your antialiasing setting (on an LCD
724 screen), can both make the problem disappear. Alternatively, customize
725 the following variables: tex-font-script-display (how much to
726 lower/raise); tex-suscript-height-ratio (how much smaller than
727 normal); tex-suscript-height-minimum (minimum height).
729 ** Screen refresh is slow when there are special characters for which no suitable font is available
731 If the display is too slow in refreshing when you scroll to a new
732 region, or when you edit the buffer, it might be due to the fact that
733 some characters cannot be displayed in the default font, and Emacs is
734 spending too much time in looking for a suitable font to display them.
736 You can suspect this if you have several characters that are displayed
737 as small rectangles containing a hexadecimal code inside.
739 The solution is to install the appropriate fonts on your machine. For
740 instance if you are editing a text with a lot of math symbols, then
741 installing a font like 'Symbola' should solve this problem.
743 * Internationalization problems
745 ** M-{ does not work on a Spanish PC keyboard.
747 Many Spanish keyboards seem to ignore that combination. Emacs can't
748 do anything about it.
750 ** International characters aren't displayed under X.
754 XFree86 4 contains many fonts in iso10646-1 encoding which have
755 minimal character repertoires (whereas the encoding part of the font
756 name is meant to be a reasonable indication of the repertoire
757 according to the XLFD spec). Emacs may choose one of these to display
758 characters from the mule-unicode charsets and then typically won't be
759 able to find the glyphs to display many characters. (Check with C-u
760 C-x = .) To avoid this, you may need to use a fontset which sets the
761 font for the mule-unicode sets explicitly. E.g. to use GNU unifont,
762 include in the fontset spec:
764 mule-unicode-2500-33ff:-gnu-unifont-*-iso10646-1,\
765 mule-unicode-e000-ffff:-gnu-unifont-*-iso10646-1,\
766 mule-unicode-0100-24ff:-gnu-unifont-*-iso10646-1
768 ** The UTF-8/16/7 coding systems don't encode CJK (Far Eastern) characters.
770 Emacs directly supports the Unicode BMP whose code points are in the
771 ranges 0000-33ff and e000-ffff, and indirectly supports the parts of
772 CJK characters belonging to these legacy charsets:
774 GB2312, Big5, JISX0208, JISX0212, JISX0213-1, JISX0213-2, KSC5601
776 The latter support is done in Utf-Translate-Cjk mode (turned on by
777 default). Which Unicode CJK characters are decoded into which Emacs
778 charset is decided by the current language environment. For instance,
779 in Chinese-GB, most of them are decoded into chinese-gb2312.
781 If you read UTF-8 data with code points outside these ranges, the
782 characters appear in the buffer as raw bytes of the original UTF-8
783 (composed into a single quasi-character) and they will be written back
784 correctly as UTF-8, assuming you don't break the composed sequences.
785 If you read such characters from UTF-16 or UTF-7 data, they are
786 substituted with the Unicode 'replacement character', and you lose
789 ** Accented ISO-8859-1 characters are displayed as | or _.
791 Try other font set sizes (S-mouse-1). If the problem persists with
792 other sizes as well, your text is corrupted, probably through software
793 that is not 8-bit clean. If the problem goes away with another font
794 size, it's probably because some fonts pretend to be ISO-8859-1 fonts
795 when they are really ASCII fonts. In particular the schumacher-clean
796 fonts have this bug in some versions of X.
798 To see what glyphs are included in a font, use 'xfd', like this:
800 xfd -fn -schumacher-clean-medium-r-normal--12-120-75-75-c-60-iso8859-1
802 If this shows only ASCII glyphs, the font is indeed the source of the problem.
804 The solution is to remove the corresponding lines from the appropriate
805 'fonts.alias' file, then run 'mkfontdir' in that directory, and then run
808 ** The 'oc-unicode' package doesn't work with Emacs 21.
810 This package tries to define more private charsets than there are free
811 slots now. The current built-in Unicode support is actually more
812 flexible. (Use option 'utf-translate-cjk-mode' if you need CJK
813 support.) Files encoded as emacs-mule using oc-unicode aren't
814 generally read correctly by Emacs 21.
818 ** X keyboard problems
820 *** You "lose characters" after typing Compose Character key.
822 This is because the Compose Character key is defined as the keysym
823 Multi_key, and Emacs (seeing that) does the proper X
824 character-composition processing. If you don't want your Compose key
825 to do that, you can redefine it with xmodmap.
827 For example, here's one way to turn it into a Meta key:
829 xmodmap -e "keysym Multi_key = Meta_L"
831 If all users at your site of a particular keyboard prefer Meta to
832 Compose, you can make the remapping happen automatically by adding the
833 xmodmap command to the xdm setup script for that display.
835 *** Using X Window System, control-shift-leftbutton makes Emacs hang.
837 Use the shell command 'xset bc' to make the old X Menu package work.
839 *** C-SPC fails to work on Fedora GNU/Linux (or with fcitx input method).
841 Fedora Core 4 steals the C-SPC key by default for the 'iiimx' program
842 which is the input method for some languages. It blocks Emacs users
843 from using the C-SPC key for 'set-mark-command'.
845 One solutions is to remove the '<Ctrl>space' from the 'Iiimx' file
846 which can be found in the '/usr/lib/X11/app-defaults' directory.
847 However, that requires root access.
849 Another is to specify 'Emacs*useXIM: false' in your X resources.
851 Another is to build Emacs with the '--without-xim' configure option.
853 The same problem happens on any other system if you are using fcitx
854 (Chinese input method) which by default use C-SPC for toggling. If
855 you want to use fcitx with Emacs, you have two choices. Toggle fcitx
856 by another key (e.g. C-\) by modifying ~/.fcitx/config, or be
857 accustomed to use C-@ for 'set-mark-command'.
859 *** Link-time optimization with clang doesn't work on Fedora 20.
861 As of May 2014, Fedora 20 has broken LLVMgold.so plugin support in clang
862 (tested with clang-3.4-6.fc20) - 'clang --print-file-name=LLVMgold.so'
863 prints 'LLVMgold.so' instead of full path to plugin shared library, and
864 'clang -flto' is unable to find the plugin with the following error:
866 /bin/ld: error: /usr/bin/../lib/LLVMgold.so: could not load plugin library:
867 /usr/bin/../lib/LLVMgold.so: cannot open shared object file: No such file
870 The only way to avoid this is to build your own clang from source code
871 repositories, as described at http://clang.llvm.org/get_started.html.
873 *** M-SPC seems to be ignored as input.
875 See if your X server is set up to use this as a command
876 for character composition.
878 *** The S-C-t key combination doesn't get passed to Emacs on X.
880 This happens because some X configurations assign the Ctrl-Shift-t
881 combination the same meaning as the Multi_key. The offending
882 definition is in the file '...lib/X11/locale/iso8859-1/Compose'; there
883 might be other similar combinations which are grabbed by X for similar
886 We think that this can be countermanded with the 'xmodmap' utility, if
887 you want to be able to bind one of these key sequences within Emacs.
889 *** Under X, C-v and/or other keys don't work.
891 These may have been intercepted by your window manager.
892 See the WM's documentation for how to change this.
894 *** Clicking C-mouse-2 in the scroll bar doesn't split the window.
896 This currently doesn't work with scroll-bar widgets (and we don't know
897 a good way of implementing it with widgets). If Emacs is configured
898 --without-toolkit-scroll-bars, C-mouse-2 on the scroll bar does work.
900 *** Inability to send an Alt-modified key, when Emacs is communicating
901 directly with an X server.
903 If you have tried to bind an Alt-modified key as a command, and it
904 does not work to type the command, the first thing you should check is
905 whether the key is getting through to Emacs. To do this, type C-h c
906 followed by the Alt-modified key. C-h c should say what kind of event
907 it read. If it says it read an Alt-modified key, then make sure you
908 have made the key binding correctly.
910 If C-h c reports an event that doesn't have the Alt modifier, it may
911 be because your X server has no key for the Alt modifier. The X
912 server that comes from MIT does not set up the Alt modifier by default.
914 If your keyboard has keys named Alt, you can enable them as follows:
916 xmodmap -e 'add mod2 = Alt_L'
917 xmodmap -e 'add mod2 = Alt_R'
919 If the keyboard has just one key named Alt, then only one of those
920 commands is needed. The modifier 'mod2' is a reasonable choice if you
921 are using an unmodified MIT version of X. Otherwise, choose any
922 modifier bit not otherwise used.
924 If your keyboard does not have keys named Alt, you can use some other
925 keys. Use the keysym command in xmodmap to turn a function key (or
926 some other 'spare' key) into Alt_L or into Alt_R, and then use the
927 commands show above to make them modifier keys.
929 Note that if you have Alt keys but no Meta keys, Emacs translates Alt
930 into Meta. This is because of the great importance of Meta in Emacs.
932 ** Window-manager and toolkit-related problems
934 *** Emacs built with GTK+ toolkit produces corrupted display on HiDPI screen
936 This can happen if you set GDK_SCALE=2 in the environment or in your
937 '.xinitrc' file. (This setting is usually accompanied by
938 GDK_DPI_SCALE=0.5.) Emacs can not support these settings correctly,
939 as it doesn't use GTK+ exclusively. The result is that sometimes
940 widgets like the scroll bar are displayed incorrectly, and frames
941 could be displayed "cropped" to only part of the stuff that should be
944 The workaround is to explicitly disable these settings when invoking
945 Emacs, for example (from a Posix shell prompt):
947 $ GDK_SCALE=1 GDK_DPI_SCALE=1 emacs
949 *** Emacs built with GTK+ toolkit can unexpectedly widen frames
951 This resizing takes place when a frame is not wide enough to accommodate
952 its entire menu bar. Typically, it occurs when switching buffers or
953 changing a buffer's major mode and the new mode adds entries to the menu
954 bar. The frame is then widened by the window manager so that the menu
955 bar is fully shown. Subsequently switching to another buffer or
956 changing the buffer's mode will not shrink the frame back to its
957 previous width. The height of the frame remains unaltered. Apparently,
958 the failure is also dependent on the chosen font.
960 The resizing is usually accompanied by console output like
962 Gtk-CRITICAL **: gtk_distribute_natural_allocation: assertion 'extra_space >= 0' failed
964 It's not clear whether the GTK version used has any impact on the
965 occurrence of the failure. So far, the failure has been observed with
966 GTK+ versions 3.4.2, 3.14.5 and 3.18.7. However, another 3.4.2 build
967 does not exhibit the bug.
969 Some window managers (Xfce) apparently work around this failure by
970 cropping the menu bar. With other windows managers, it's possible to
971 shrink the frame manually after the problem occurs, e.g. by dragging the
972 frame's border with the mouse. However, some window managers have been
973 reported to refuse such attempts and snap back to the width needed to
974 show the full menu bar (wmii) or at least cause the screen to flicker
975 during such resizing attempts (i3, IceWM).
977 See also http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15700,
978 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=22000,
979 http://debbugs.gnu.org/cgi/bugreport.cgi?bug=22898 and
980 http://lists.gnu.org/archive/html/emacs-devel/2016-07/msg00154.html.
982 *** Metacity: Resizing Emacs or ALT-Tab causes X to be unresponsive.
984 This happens sometimes when using Metacity. Resizing Emacs or ALT-Tab:bing
985 makes the system unresponsive to the mouse or the keyboard. Killing Emacs
986 or shifting out from X and back again usually cures it (i.e. Ctrl-Alt-F1
987 and then Alt-F7). A bug for it is here:
988 https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/231034.
989 Note that a permanent fix seems to be to disable "assistive technologies".
991 *** Gnome: Emacs receives input directly from the keyboard, bypassing XIM.
993 This seems to happen when gnome-settings-daemon version 2.12 or later
994 is running. If gnome-settings-daemon is not running, Emacs receives
995 input through XIM without any problem. Furthermore, this seems only
996 to happen in *.UTF-8 locales; zh_CN.GB2312 and zh_CN.GBK locales, for
997 example, work fine. A bug report has been filed in the Gnome
998 bugzilla: http://bugzilla.gnome.org/show_bug.cgi?id=357032
1000 *** Gnome: Emacs's xterm-mouse-mode doesn't work on the Gnome terminal.
1002 A symptom of this bug is that double-clicks insert a control sequence
1003 into the buffer. The reason this happens is an apparent
1004 incompatibility of the Gnome terminal with Xterm, which also affects
1005 other programs using the Xterm mouse interface. A problem report has
1008 *** KDE: When running on KDE, colors or fonts are not as specified for Emacs,
1011 For example, you could see background you set for Emacs only in the
1012 empty portions of the Emacs display, while characters have some other
1015 This happens because KDE's defaults apply its color and font
1016 definitions even to applications that weren't compiled for KDE. The
1017 solution is to uncheck the "Apply fonts and colors to non-KDE apps"
1018 option in Preferences->Look&Feel->Style (KDE 2). In KDE 3, this option
1019 is in the "Colors" section, rather than "Style".
1021 Alternatively, if you do want the KDE defaults to apply to other
1022 applications, but not to Emacs, you could modify the file 'Emacs.ad'
1023 (should be in the '/usr/share/apps/kdisplay/app-defaults/' directory)
1024 so that it doesn't set the default background and foreground only for
1025 Emacs. For example, make sure the following resources are either not
1026 present or commented out:
1028 Emacs.default.attributeForeground
1029 Emacs.default.attributeBackground
1033 It is also reported that a bug in the gtk-engines-qt engine can cause this if
1034 Emacs is compiled with Gtk+.
1035 The bug is fixed in version 0.7 or newer of gtk-engines-qt.
1037 *** KDE: Emacs hangs on KDE when a large portion of text is killed.
1039 This is caused by a bug in the KDE applet 'klipper' which periodically
1040 requests the X clipboard contents from applications. Early versions
1041 of klipper don't implement the ICCCM protocol for large selections,
1042 which leads to Emacs being flooded with selection requests. After a
1043 while, Emacs may print a message:
1045 Timed out waiting for property-notify event
1047 A workaround is to not use 'klipper'. Upgrading 'klipper' to the one
1048 coming with KDE 3.3 or later also solves the problem.
1050 *** KDE / Plasma 5: Emacs exhausts memory and needs to be killed
1052 This problem occurs when large selections contain mixed line endings
1053 (i.e. the buffer has LF line endings, but in some parts CRLF is used).
1054 The source of the problem is currently under investigation, older
1055 versions of Emacs up to 24.5 just hang for a few seconds and then
1056 return with the message "Timed out waiting for property-notify event"
1057 as described in the previous note. As a workaround, go to the
1058 settings dialog for the Clipboard widget and select the option "Ignore
1061 Note: Plasma 5 has replaced the separate klipper process from earlier
1062 KDE versions with functionality directly integrated into plasmashell,
1063 so even if you've previously did not use klipper this will affect you.
1064 Also, all configuration you might have done to klipper is not used by
1065 the new Clipboard widget / plasmoid since it uses its own settings.
1066 You can hide the Clipboard widget by removing its entry from the
1067 system tray settings "Extra Items", but it's not clear if the
1068 underlying functionality in plasmashell gets fully disabled as well.
1069 At least a restart of plasmashell is required for the clipboard
1070 history to be cleared.
1072 *** CDE: Frames may cover dialogs they created when using CDE.
1074 This can happen if you have "Allow Primary Windows On Top" enabled which
1075 seems to be the default in the Common Desktop Environment.
1076 To change, go in to "Desktop Controls" -> "Window Style Manager"
1077 and uncheck "Allow Primary Windows On Top".
1079 *** Xaw3d : When using Xaw3d scroll bars without arrows, the very first mouse
1080 click in a scroll bar might be ignored by the scroll bar widget. This
1081 is probably a bug in Xaw3d; when Xaw3d is compiled with arrows, the
1084 *** Xaw: There are known binary incompatibilities between Xaw, Xaw3d, neXtaw,
1085 XawM and the few other derivatives of Xaw. So when you compile with
1086 one of these, it may not work to dynamically link with another one.
1087 For example, strange problems, such as Emacs exiting when you type
1088 "C-x 1", were reported when Emacs compiled with Xaw3d and libXaw was
1089 used with neXtaw at run time.
1091 The solution is to rebuild Emacs with the toolkit version you actually
1092 want to use, or set LD_PRELOAD to preload the same toolkit version you
1095 *** Open Motif: Problems with file dialogs in Emacs built with Open Motif.
1097 When Emacs 21 is built with Open Motif 2.1, it can happen that the
1098 graphical file dialog boxes do not work properly. The "OK", "Filter"
1099 and "Cancel" buttons do not respond to mouse clicks. Dragging the
1100 file dialog window usually causes the buttons to work again.
1102 As a workaround, you can try building Emacs using Motif or LessTif instead.
1104 Another workaround is not to use the mouse to trigger file prompts,
1105 but to use the keyboard. This way, you will be prompted for a file in
1106 the minibuffer instead of a graphical file dialog.
1108 *** LessTif: Problems in Emacs built with LessTif.
1110 The problems seem to depend on the version of LessTif and the Motif
1111 emulation for which it is set up.
1113 Only the Motif 1.2 emulation seems to be stable enough in LessTif.
1114 LessTif 0.92-17's Motif 1.2 emulation seems to work okay on FreeBSD.
1115 On GNU/Linux systems, lesstif-0.92.6 configured with "./configure
1116 --enable-build-12 --enable-default-12" is reported to be the most
1117 successful. The binary GNU/Linux package
1118 lesstif-devel-0.92.0-1.i386.rpm was reported to have problems with
1121 On some systems, Emacs occasionally locks up, grabbing all mouse and
1122 keyboard events. We don't know what causes these problems; they are
1123 not reproducible by Emacs developers.
1125 *** Motif: The Motif version of Emacs paints the screen a solid color.
1127 This has been observed to result from the following X resource:
1129 Emacs*default.attributeFont: -*-courier-medium-r-*-*-*-140-*-*-*-*-iso8859-*
1131 That the resource has this effect indicates a bug in something, but we
1132 do not know what. If it is an Emacs bug, we hope someone can
1133 explain what the bug is so we can fix it. In the mean time, removing
1134 the resource prevents the problem.
1136 ** General X problems
1138 *** Redisplay using X is much slower than previous Emacs versions.
1140 We've noticed that certain X servers draw the text much slower when
1141 scroll bars are on the left. We don't know why this happens. If this
1142 happens to you, you can work around it by putting the scroll bars
1143 on the right (as they were in Emacs 19).
1145 Here's how to do this:
1147 (set-scroll-bar-mode 'right)
1149 If you're not sure whether (or how much) this problem affects you,
1150 try that and see how much difference it makes. To set things back
1153 (set-scroll-bar-mode 'left)
1155 *** Error messages about undefined colors on X.
1157 The messages might say something like this:
1159 Unable to load color "grey95"
1161 (typically, in the '*Messages*' buffer), or something like this:
1163 Error while displaying tooltip: (error Undefined color lightyellow)
1165 These problems could happen if some other X program has used up too
1166 many colors of the X palette, leaving Emacs with insufficient system
1167 resources to load all the colors it needs.
1169 A solution is to exit the offending X programs before starting Emacs.
1171 "undefined color" messages can also occur if the RgbPath entry in the
1172 X configuration file is incorrect, or the rgb.txt file is not where
1173 X expects to find it.
1175 *** Improving performance with slow X connections.
1177 There are several ways to improve this performance, any subset of which can
1178 be carried out at the same time:
1180 1) If you don't need X Input Methods (XIM) for entering text in some
1181 language you use, you can improve performance on WAN links by using
1182 the X resource useXIM to turn off use of XIM. This does not affect
1183 the use of Emacs's own input methods, which are part of the Leim
1186 2) If the connection is very slow, you might also want to consider
1187 switching off scroll bars, menu bar, and tool bar. Adding the
1188 following forms to your .emacs file will accomplish that, but only
1189 after the initial frame is displayed:
1191 (scroll-bar-mode -1)
1195 For still quicker startup, put these X resources in your
1196 .Xresources or .Xdefaults file:
1198 Emacs.verticalScrollBars: off
1202 3) Use ssh to forward the X connection, and enable compression on this
1203 forwarded X connection (ssh -XC remotehostname emacs ...).
1205 4) Use lbxproxy on the remote end of the connection. This is an interface
1206 to the low bandwidth X extension in most modern X servers, which
1207 improves performance dramatically, at the slight expense of correctness
1208 of the X protocol. lbxproxy achieves the performance gain by grouping
1209 several X requests in one TCP packet and sending them off together,
1210 instead of requiring a round-trip for each X request in a separate
1211 packet. The switches that seem to work best for emacs are:
1212 -noatomsfile -nowinattr -cheaterrors -cheatevents
1213 Note that the -nograbcmap option is known to cause problems.
1214 For more about lbxproxy, see:
1215 http://www.x.org/archive/X11R6.8.0/doc/lbxproxy.1.html
1217 5) If copying and killing is slow, try to disable the interaction with the
1218 native system's clipboard by adding these lines to your .emacs file:
1219 (setq interprogram-cut-function nil)
1220 (setq interprogram-paste-function nil)
1222 *** Emacs gives the error, Couldn't find per display information.
1224 This can result if the X server runs out of memory because Emacs uses
1225 a large number of fonts. On systems where this happens, C-h h is
1228 We do not know of a way to prevent the problem.
1230 *** Emacs does not notice when you release the mouse.
1232 There are reports that this happened with (some) Microsoft mice and
1233 that replacing the mouse made it stop.
1235 *** You can't select from submenus (in the X toolkit version).
1237 On certain systems, mouse-tracking and selection in top-level menus
1238 works properly with the X toolkit, but neither of them works when you
1239 bring up a submenu (such as Bookmarks or Compare or Apply Patch, in
1242 This works on most systems. There is speculation that the failure is
1243 due to bugs in old versions of X toolkit libraries, but no one really
1244 knows. If someone debugs this and finds the precise cause, perhaps a
1245 workaround can be found.
1247 *** An error message such as 'X protocol error: BadMatch (invalid
1248 parameter attributes) on protocol request 93'.
1250 This comes from having an invalid X resource, such as
1252 (which is invalid because it specifies a color name for something
1253 that isn't a color.)
1255 The fix is to correct your X resources.
1257 *** Slow startup on X11R6 with X windows.
1259 If Emacs takes two minutes to start up on X11R6, see if your X
1260 resources specify any Adobe fonts. That causes the type-1 font
1261 renderer to start up, even if the font you asked for is not a type-1
1264 One way to avoid this problem is to eliminate the type-1 fonts from
1265 your font path, like this:
1267 xset -fp /usr/X11R6/lib/X11/fonts/Type1/
1269 *** Pull-down menus appear in the wrong place, in the toolkit version of Emacs.
1271 An X resource of this form can cause the problem:
1273 Emacs*geometry: 80x55+0+0
1275 This resource is supposed to apply, and does apply, to the menus
1276 individually as well as to Emacs frames. If that is not what you
1277 want, rewrite the resource.
1279 To check thoroughly for such resource specifications, use 'xrdb
1280 -query' to see what resources the X server records, and also look at
1281 the user's ~/.Xdefaults and ~/.Xdefaults-* files.
1283 *** Emacs running under X Window System does not handle mouse clicks.
1284 *** 'emacs -geometry 80x20' finds a file named '80x20'.
1286 One cause of such problems is having (setq term-file-prefix nil) in
1287 your .emacs file. Another cause is a bad value of EMACSLOADPATH in
1290 *** X doesn't work if DISPLAY uses a hostname.
1292 People have reported kernel bugs in certain systems that cause Emacs
1293 not to work with X if DISPLAY is set using a host name. But
1294 the problem does not occur if DISPLAY is set to 'unix:0.0'. I think
1295 the bug has to do with SIGIO or FIONREAD.
1297 You may be able to compensate for the bug by doing (set-input-mode nil nil).
1298 However, that has the disadvantage of turning off interrupts, so that
1299 you are unable to quit out of a Lisp program by typing C-g.
1301 *** Prevent double pastes in X
1303 The problem: a region, such as a command, is pasted twice when you copy
1304 it with your mouse from GNU Emacs to an xterm or an RXVT shell in X.
1305 The solution: try the following in your X configuration file,
1306 /etc/X11/xorg.conf This should enable both PS/2 and USB mice for
1307 single copies. You do not need any other drivers or options.
1309 Section "InputDevice"
1310 Identifier "Generic Mouse"
1312 Option "Device" "/dev/input/mice"
1315 *** Emacs is slow to exit in X
1317 After you use e.g. C-x C-c to exit, it takes many seconds before the
1318 Emacs window disappears. If Emacs was started from a terminal, you
1321 Error saving to X clipboard manager.
1322 If the problem persists, set 'x-select-enable-clipboard-manager' to nil.
1324 As the message suggests, this problem occurs when Emacs thinks you
1325 have a clipboard manager program running, but has trouble contacting it.
1326 If you don't want to use a clipboard manager, you can set the
1327 suggested variable. Or you can make Emacs not wait so long by
1328 reducing the value of 'x-selection-timeout', either in .emacs or with
1331 Sometimes this problem is due to a bug in your clipboard manager.
1332 Updating to the latest version of the manager can help.
1333 For example, in the Xfce 4.8 desktop environment, the clipboard
1334 manager in versions of xfce4-settings-helper before 4.8.2 is buggy;
1335 https://bugzilla.xfce.org/show_bug.cgi?id=7588 .
1337 *** Warning messages when running in Ubuntu
1339 When you start Emacs you may see something like this:
1341 (emacs:2286): LIBDBUSMENU-GTK-CRITICAL **: watch_submenu: assertion
1342 'GTK_IS_MENU_SHELL(menu)' failed
1344 This happens if the Emacs binary has been renamed. The cause is the Ubuntu
1345 appmenu concept. It tries to track Emacs menus and show them in the top
1346 panel, instead of in each Emacs window. This is not properly implemented,
1347 so it fails for Emacs. The order of menus is wrong, and things like copy/paste
1348 that depend on what state Emacs is in are usually wrong (i.e. paste disabled
1349 even if you should be able to paste, and similar).
1351 You can get back menus on each frame by starting emacs like this:
1352 % env UBUNTU_MENUPROXY= emacs
1354 * Runtime problems on character terminals
1356 ** The meta key does not work on xterm.
1358 Typing M-x rings the terminal bell, and inserts a string like ";120~".
1359 For recent xterm versions (>= 216), Emacs uses xterm's modifyOtherKeys
1360 feature to generate strings for key combinations that are not
1361 otherwise usable. One circumstance in which this can cause problems
1362 is if you have specified the X resource
1364 xterm*VT100.Translations
1366 to contain translations that use the meta key. Then xterm will not
1367 use meta in modified function-keys, which confuses Emacs. To fix
1368 this, you can remove the X resource or put this in your init file:
1370 (xterm-remove-modify-other-keys)
1372 ** Emacs spontaneously displays "I-search: " at the bottom of the screen.
1374 This means that Control-S/Control-Q (XON/XOFF) "flow control" is being
1375 used. C-s/C-q flow control is bad for Emacs editors because it takes
1376 away C-s and C-q as user commands. Since editors do not output long
1377 streams of text without user commands, there is no need for a
1378 user-issuable "stop output" command in an editor; therefore, a
1379 properly designed flow control mechanism would transmit all possible
1380 input characters without interference. Designing such a mechanism is
1381 easy, for a person with at least half a brain.
1383 There are three possible reasons why flow control could be taking place:
1385 1) Terminal has not been told to disable flow control
1386 2) Insufficient padding for the terminal in use
1387 3) Some sort of terminal concentrator or line switch is responsible
1389 First of all, many terminals have a set-up mode which controls whether
1390 they generate XON/XOFF flow control characters. This must be set to
1391 "no XON/XOFF" in order for Emacs to work. (For example, on a VT220
1392 you may select "No XOFF" in the setup menu.) Sometimes there is an
1393 escape sequence that the computer can send to turn flow control off
1394 and on. If so, perhaps the termcap 'ti' string should turn flow
1395 control off, and the 'te' string should turn it on.
1397 Once the terminal has been told "no flow control", you may find it
1398 needs more padding. The amount of padding Emacs sends is controlled
1399 by the termcap entry for the terminal in use, and by the output baud
1400 rate as known by the kernel. The shell command 'stty' will print
1401 your output baud rate; 'stty' with suitable arguments will set it if
1402 it is wrong. Setting to a higher speed causes increased padding. If
1403 the results are wrong for the correct speed, there is probably a
1404 problem in the termcap entry. You must speak to a local Unix wizard
1405 to fix this. Perhaps you are just using the wrong terminal type.
1407 For terminals that lack a "no flow control" mode, sometimes just
1408 giving lots of padding will prevent actual generation of flow control
1409 codes. You might as well try it.
1411 If you are really unlucky, your terminal is connected to the computer
1412 through a concentrator which sends XON/XOFF flow control to the
1413 computer, or it insists on sending flow control itself no matter how
1414 much padding you give it. Unless you can figure out how to turn flow
1415 control off on this concentrator (again, refer to your local wizard),
1416 you are screwed! You should have the terminal or concentrator
1417 replaced with a properly designed one. In the mean time, some drastic
1418 measures can make Emacs semi-work.
1420 You can make Emacs ignore C-s and C-q and let the operating system
1421 handle them. To do this on a per-session basis, just type M-x
1422 enable-flow-control RET. You will see a message that C-\ and C-^ are
1423 now translated to C-s and C-q. (Use the same command M-x
1424 enable-flow-control to turn *off* this special mode. It toggles flow
1427 If C-\ and C-^ are inconvenient for you (for example, if one of them
1428 is the escape character of your terminal concentrator), you can choose
1429 other characters by setting the variables flow-control-c-s-replacement
1430 and flow-control-c-q-replacement. But choose carefully, since all
1431 other control characters are already used by emacs.
1433 IMPORTANT: if you type C-s by accident while flow control is enabled,
1434 Emacs output will freeze, and you will have to remember to type C-q in
1437 If you work in an environment where a majority of terminals of a
1438 certain type are flow control hobbled, you can use the function
1439 'enable-flow-control-on' to turn on this flow control avoidance scheme
1440 automatically. Here is an example:
1442 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1444 If this isn't quite correct (e.g. you have a mixture of flow-control hobbled
1445 and good vt200 terminals), you can still run enable-flow-control
1448 I have no intention of ever redesigning the Emacs command set for the
1449 assumption that terminals use C-s/C-q flow control. XON/XOFF flow
1450 control technique is a bad design, and terminals that need it are bad
1451 merchandise and should not be purchased. Now that X is becoming
1452 widespread, XON/XOFF seems to be on the way out. If you can get some
1453 use out of GNU Emacs on inferior terminals, more power to you, but I
1454 will not make Emacs worse for properly designed systems for the sake
1455 of inferior systems.
1457 ** Control-S and Control-Q commands are ignored completely.
1459 For some reason, your system is using brain-damaged C-s/C-q flow
1460 control despite Emacs's attempts to turn it off. Perhaps your
1461 terminal is connected to the computer through a concentrator
1462 that wants to use flow control.
1464 You should first try to tell the concentrator not to use flow control.
1465 If you succeed in this, try making the terminal work without
1466 flow control, as described in the preceding section.
1468 If that line of approach is not successful, map some other characters
1469 into C-s and C-q using keyboard-translate-table. The example above
1470 shows how to do this with C-^ and C-\.
1472 ** Screen is updated wrong, but only on one kind of terminal.
1474 This could mean that the termcap entry you are using for that
1475 terminal is wrong, or it could mean that Emacs has a bug handling
1476 the combination of features specified for that terminal.
1478 The first step in tracking this down is to record what characters
1479 Emacs is sending to the terminal. Execute the Lisp expression
1480 (open-termscript "./emacs-script") to make Emacs write all
1481 terminal output into the file ~/emacs-script as well; then do
1482 what makes the screen update wrong, and look at the file
1483 and decode the characters using the manual for the terminal.
1484 There are several possibilities:
1486 1) The characters sent are correct, according to the terminal manual.
1488 In this case, there is no obvious bug in Emacs, and most likely you
1489 need more padding, or possibly the terminal manual is wrong.
1491 2) The characters sent are incorrect, due to an obscure aspect
1492 of the terminal behavior not described in an obvious way by termcap.
1494 This case is hard. It will be necessary to think of a way for
1495 Emacs to distinguish between terminals with this kind of behavior
1496 and other terminals that behave subtly differently but are
1497 classified the same by termcap; or else find an algorithm for
1498 Emacs to use that avoids the difference. Such changes must be
1499 tested on many kinds of terminals.
1501 3) The termcap entry is wrong.
1503 See the file etc/TERMS for information on changes
1504 that are known to be needed in commonly used termcap entries
1505 for certain terminals.
1507 4) The characters sent are incorrect, and clearly cannot be
1508 right for any terminal with the termcap entry you were using.
1510 This is unambiguously an Emacs bug, and can probably be fixed
1511 in termcap.c, tparam.c, term.c, scroll.c, cm.c or dispnew.c.
1513 ** Control-S and Control-Q commands are ignored completely on a net connection.
1515 Some versions of rlogin (and possibly telnet) do not pass flow
1516 control characters to the remote system to which they connect.
1517 On such systems, emacs on the remote system cannot disable flow
1518 control on the local system. Sometimes 'rlogin -8' will avoid this problem.
1520 One way to cure this is to disable flow control on the local host
1521 (the one running rlogin, not the one running rlogind) using the
1522 stty command, before starting the rlogin process. On many systems,
1523 "stty start u stop u" will do this. On some systems, use
1524 "stty -ixon" instead.
1526 Some versions of tcsh will prevent even this from working. One way
1527 around this is to start another shell before starting rlogin, and
1528 issue the stty command to disable flow control from that shell.
1530 If none of these methods work, the best solution is to type
1531 M-x enable-flow-control at the beginning of your emacs session, or
1532 if you expect the problem to continue, add a line such as the
1533 following to your .emacs (on the host running rlogind):
1535 (enable-flow-control-on "vt200" "vt300" "vt101" "vt131")
1537 See the entry about spontaneous display of I-search (above) for more info.
1539 ** Output from Control-V is slow.
1541 On many bit-map terminals, scrolling operations are fairly slow.
1542 Often the termcap entry for the type of terminal in use fails
1543 to inform Emacs of this. The two lines at the bottom of the screen
1544 before a Control-V command are supposed to appear at the top after
1545 the Control-V command. If Emacs thinks scrolling the lines is fast,
1546 it will scroll them to the top of the screen.
1548 If scrolling is slow but Emacs thinks it is fast, the usual reason is
1549 that the termcap entry for the terminal you are using does not
1550 specify any padding time for the 'al' and 'dl' strings. Emacs
1551 concludes that these operations take only as much time as it takes to
1552 send the commands at whatever line speed you are using. You must
1553 fix the termcap entry to specify, for the 'al' and 'dl', as much
1554 time as the operations really take.
1556 Currently Emacs thinks in terms of serial lines which send characters
1557 at a fixed rate, so that any operation which takes time for the
1558 terminal to execute must also be padded. With bit-map terminals
1559 operated across networks, often the network provides some sort of
1560 flow control so that padding is never needed no matter how slow
1561 an operation is. You must still specify a padding time if you want
1562 Emacs to realize that the operation takes a long time. This will
1563 cause padding characters to be sent unnecessarily, but they do
1564 not really cost much. They will be transmitted while the scrolling
1565 is happening and then discarded quickly by the terminal.
1567 Most bit-map terminals provide commands for inserting or deleting
1568 multiple lines at once. Define the 'AL' and 'DL' strings in the
1569 termcap entry to say how to do these things, and you will have
1570 fast output without wasted padding characters. These strings should
1571 each contain a single %-spec saying how to send the number of lines
1572 to be scrolled. These %-specs are like those in the termcap
1575 You should also define the 'IC' and 'DC' strings if your terminal
1576 has a command to insert or delete multiple characters. These
1577 take the number of positions to insert or delete as an argument.
1579 A 'cs' string to set the scrolling region will reduce the amount
1580 of motion you see on the screen when part of the screen is scrolled.
1582 ** You type Control-H (Backspace) expecting to delete characters.
1584 Put 'stty dec' in your .login file and your problems will disappear
1587 The choice of Backspace for erasure was based on confusion, caused by
1588 the fact that backspacing causes erasure (later, when you type another
1589 character) on most display terminals. But it is a mistake. Deletion
1590 of text is not the same thing as backspacing followed by failure to
1591 overprint. I do not wish to propagate this confusion by conforming
1594 For this reason, I believe 'stty dec' is the right mode to use,
1595 and I have designed Emacs to go with that. If there were a thousand
1596 other control characters, I would define Control-h to delete as well;
1597 but there are not very many other control characters, and I think
1598 that providing the most mnemonic possible Help character is more
1599 important than adapting to people who don't use 'stty dec'.
1601 If you are obstinate about confusing buggy overprinting with deletion,
1602 you can redefine Backspace in your .emacs file:
1603 (global-set-key "\b" 'delete-backward-char)
1604 You can probably access help-command via f1.
1606 ** Colors are not available on a tty or in xterm.
1608 Emacs 21 supports colors on character terminals and terminal
1609 emulators, but this support relies on the terminfo or termcap database
1610 entry to specify that the display supports color. Emacs looks at the
1611 "Co" capability for the terminal to find out how many colors are
1612 supported; it should be non-zero to activate the color support within
1613 Emacs. (Most color terminals support 8 or 16 colors.) If your system
1614 uses terminfo, the name of the capability equivalent to "Co" is
1617 In addition to the "Co" capability, Emacs needs the "op" (for
1618 "original pair") capability, which tells how to switch the terminal
1619 back to the default foreground and background colors. Emacs will not
1620 use colors if this capability is not defined. If your terminal entry
1621 doesn't provide such a capability, try using the ANSI standard escape
1622 sequence \E[00m (that is, define a new termcap/terminfo entry and make
1623 it use your current terminal's entry plus \E[00m for the "op"
1626 Finally, the "NC" capability (terminfo name: "ncv") tells Emacs which
1627 attributes cannot be used with colors. Setting this capability
1628 incorrectly might have the effect of disabling colors; try setting
1629 this capability to '0' (zero) and see if that helps.
1631 Emacs uses the database entry for the terminal whose name is the value
1632 of the environment variable TERM. With 'xterm', a common terminal
1633 entry that supports color is 'xterm-color', so setting TERM's value to
1634 'xterm-color' might activate the color support on an xterm-compatible
1637 Beginning with version 22.1, Emacs supports the --color command-line
1638 option which may be used to force Emacs to use one of a few popular
1639 modes for getting colors on a tty. For example, --color=ansi8 sets up
1640 for using the ANSI-standard escape sequences that support 8 colors.
1642 Some modes do not use colors unless you turn on the Font-lock mode.
1643 Some people have long ago set their '~/.emacs' files to turn on
1644 Font-lock on X only, so they won't see colors on a tty. The
1645 recommended way of turning on Font-lock is by typing "M-x
1646 global-font-lock-mode RET" or by customizing the variable
1647 'global-font-lock-mode'.
1649 ** Unexpected characters inserted into the buffer when you start Emacs.
1650 See e.g. <URL:http://debbugs.gnu.org/11129>
1652 This can happen when you start Emacs in -nw mode in an Xterm.
1653 For example, in the *scratch* buffer, you might see something like:
1657 This is more likely to happen if you are using Emacs over a slow
1658 connection, and begin typing before Emacs is ready to respond.
1660 This occurs when Emacs tries to query the terminal to see what
1661 capabilities it supports, and gets confused by the answer.
1662 To avoid it, set xterm-extra-capabilities to a value other than
1663 'check' (the default). See that variable's documentation (in
1664 term/xterm.el) for more details.
1666 * Runtime problems specific to individual Unix variants
1670 *** GNU/Linux: Process output is corrupted.
1672 There is a bug in Linux kernel 2.6.10 PTYs that can cause emacs to
1673 read corrupted process output.
1675 *** GNU/Linux: Remote access to CVS with SSH causes file corruption.
1677 If you access a remote CVS repository via SSH, files may be corrupted
1678 due to bad interaction between CVS, SSH, and libc.
1680 To fix the problem, save the following script into a file, make it
1681 executable, and set CVS_RSH environment variable to the file name of
1685 exec 2> >(exec cat >&2 2>/dev/null)
1688 *** GNU/Linux: Truncated svn annotate output with SSH.
1689 http://debbugs.gnu.org/7791
1691 The symptoms are: you are accessing a svn repository over SSH.
1692 You use vc-annotate on a large (several thousand line) file, and the
1693 result is truncated around the 1000 line mark. It works fine with
1694 other access methods (e.g. http), or from outside Emacs.
1696 This may be a similar libc/SSH issue to the one mentioned above for CVS.
1697 A similar workaround seems to be effective: create a script with the
1698 same contents as the one used above for CVS_RSH, and set the SVN_SSH
1699 environment variable to point to it.
1701 *** GNU/Linux: After upgrading to a newer version of Emacs,
1702 the Meta key stops working.
1704 This was reported to happen on a GNU/Linux system distributed by
1705 Mandrake. The reason is that the previous version of Emacs was
1706 modified by Mandrake to make the Alt key act as the Meta key, on a
1707 keyboard where the Windows key is the one which produces the Meta
1708 modifier. A user who started using a newer version of Emacs, which
1709 was not hacked by Mandrake, expected the Alt key to continue to act as
1710 Meta, and was astonished when that didn't happen.
1712 The solution is to find out what key on your keyboard produces the Meta
1713 modifier, and use that key instead. Try all of the keys to the left
1714 and to the right of the space bar, together with the 'x' key, and see
1715 which combination produces "M-x" in the echo area. You can also use
1716 the 'xmodmap' utility to show all the keys which produce a Meta
1719 xmodmap -pk | grep -Ei "meta|alt"
1721 A more convenient way of finding out which keys produce a Meta modifier
1722 is to use the 'xkbprint' utility, if it's available on your system:
1724 xkbprint 0:0 /tmp/k.ps
1726 This produces a PostScript file '/tmp/k.ps' with a picture of your
1727 keyboard; printing that file on a PostScript printer will show what
1728 keys can serve as Meta.
1730 The 'xkeycaps' also shows a visual representation of the current
1731 keyboard settings. It also allows to modify them.
1733 *** GNU/Linux: slow startup on Linux-based GNU systems.
1735 People using systems based on the Linux kernel sometimes report that
1736 startup takes 10 to 15 seconds longer than 'usual'.
1738 This is because Emacs looks up the host name when it starts.
1739 Normally, this takes negligible time; the extra delay is due to
1740 improper system configuration. This problem can occur for both
1741 networked and non-networked machines.
1743 Here is how to fix the configuration. It requires being root.
1745 **** Networked Case.
1747 First, make sure the files '/etc/hosts' and '/etc/host.conf' both
1748 exist. The first line in the '/etc/hosts' file should look like this
1749 (replace HOSTNAME with your host name):
1753 Also make sure that the '/etc/host.conf' files contains the following
1759 Any changes, permanent and temporary, to the host name should be
1760 indicated in the '/etc/hosts' file, since it acts a limited local
1761 database of addresses and names (e.g., some SLIP connections
1762 dynamically allocate ip addresses).
1764 **** Non-Networked Case.
1766 The solution described in the networked case applies here as well.
1767 However, if you never intend to network your machine, you can use a
1768 simpler solution: create an empty '/etc/host.conf' file. The command
1769 'touch /etc/host.conf' suffices to create the file. The '/etc/hosts'
1770 file is not necessary with this approach.
1772 *** GNU/Linux: Emacs on a tty switches the cursor to large blinking block.
1774 This was reported to happen on some GNU/Linux systems which use
1775 ncurses version 5.0, but could be relevant for other versions as well.
1776 These versions of ncurses come with a 'linux' terminfo entry, where
1777 the "cvvis" capability (termcap "vs") is defined as "\E[?25h\E[?8c"
1778 (show cursor, change size). This escape sequence switches on a
1779 blinking hardware text-mode cursor whose size is a full character
1780 cell. This blinking cannot be stopped, since a hardware cursor
1783 A work-around is to redefine the "cvvis" capability so that it
1784 enables a *software* cursor. The software cursor works by inverting
1785 the colors of the character at point, so what you see is a block
1786 cursor that doesn't blink. For this to work, you need to redefine
1787 the "cnorm" capability as well, so that it operates on the software
1788 cursor instead of the hardware cursor.
1790 To this end, run "infocmp linux > linux-term", edit the file
1791 'linux-term' to make both the "cnorm" and "cvvis" capabilities send
1792 the sequence "\E[?25h\E[?17;0;64c", and then run "tic linux-term" to
1793 produce a modified terminfo entry.
1795 Alternatively, if you want a blinking underscore as your Emacs cursor,
1796 set the 'visible-cursor' variable to nil in your ~/.emacs:
1797 (setq visible-cursor nil)
1799 Still other way is to change the "cvvis" capability to send the
1800 "\E[?25h\E[?0c" command.
1804 *** FreeBSD: Getting a Meta key on the console.
1806 By default, neither Alt nor any other key acts as a Meta key on
1807 FreeBSD, but this can be changed using kbdcontrol(1). Dump the
1808 current keymap to a file with the command
1810 $ kbdcontrol -d >emacs.kbd
1812 Edit emacs.kbd, and give the key you want to be the Meta key the
1813 definition 'meta'. For instance, if your keyboard has a "Windows"
1814 key with scan code 105, change the line for scan code 105 in emacs.kbd
1817 105 meta meta meta meta meta meta meta meta O
1819 to make the Windows key the Meta key. Load the new keymap with
1821 $ kbdcontrol -l emacs.kbd
1825 *** HP/UX : Shell mode gives the message, "`tty`: Ambiguous".
1827 christos@theory.tn.cornell.edu says:
1829 The problem is that in your .cshrc you have something that tries to
1830 execute 'tty'. If you are not running the shell on a real tty then
1831 tty will print "not a tty". Csh expects one word in some places,
1832 but tty is giving it back 3.
1834 The solution is to add a pair of quotes around `tty` to make it a single
1837 if (`tty` == "/dev/console")
1839 should be changed to:
1841 if ("`tty`" == "/dev/console")
1843 Even better, move things that set up terminal sections out of .cshrc
1846 *** HP/UX: 'Pid xxx killed due to text modification or page I/O error'.
1848 On HP/UX, you can get that error when the Emacs executable is on an NFS
1849 file system. HP/UX responds this way if it tries to swap in a page and
1850 does not get a response from the server within a timeout whose default
1851 value is just ten seconds.
1853 If this happens to you, extend the timeout period.
1855 *** HP/UX: The right Alt key works wrong on German HP keyboards (and perhaps
1856 other non-English HP keyboards too).
1858 This is because HP-UX defines the modifiers wrong in X. Here is a
1859 shell script to fix the problem; be sure that it is run after VUE
1860 configures the X server.
1862 xmodmap 2> /dev/null - << EOF
1863 keysym Alt_L = Meta_L
1864 keysym Alt_R = Meta_R
1869 keysym Mode_switch = NoSymbol
1871 keysym Meta_R = Mode_switch
1872 add mod2 = Mode_switch
1875 *** HP/UX: Emacs does not recognize the AltGr key.
1877 To fix this, set up a file ~/.dt/sessions/sessionetc with executable
1878 rights, containing this text:
1880 --------------------------------
1881 xmodmap 2> /dev/null - << EOF
1882 keysym Alt_L = Meta_L
1883 keysym Alt_R = Meta_R
1888 keysym Mode_switch = NoSymbol
1890 keysym Meta_R = Mode_switch
1891 add mod2 = Mode_switch
1893 --------------------------------
1895 *** HP/UX 11.0: Emacs makes HP/UX 11.0 crash.
1897 This is a bug in HPUX; HPUX patch PHKL_16260 is said to fix it.
1901 *** AIX: Trouble using ptys.
1903 People often install the pty devices on AIX incorrectly.
1904 Use 'smit pty' to reinstall them properly.
1906 *** AIXterm: Your Delete key sends a Backspace to the terminal.
1908 The solution is to include in your .Xdefaults the lines:
1910 *aixterm.Translations: #override <Key>BackSpace: string(0x7f)
1911 aixterm*ttyModes: erase ^?
1913 This makes your Backspace key send DEL (ASCII 127).
1915 *** AIX: If linking fails because libXbsd isn't found, check if you
1916 are compiling with the system's 'cc' and CFLAGS containing '-O5'. If
1917 so, you have hit a compiler bug. Please make sure to re-configure
1918 Emacs so that it isn't compiled with '-O5'.
1920 *** AIX 4.3.x or 4.4: Compiling fails.
1922 This could happen if you use /bin/c89 as your compiler, instead of
1923 the default 'cc'. /bin/c89 treats certain warnings, such as benign
1924 redefinitions of macros, as errors, and fails the build. A solution
1925 is to use the default compiler 'cc'.
1927 *** AIX 4: Some programs fail when run in a Shell buffer
1928 with an error message like No terminfo entry for "unknown".
1930 On AIX, many terminal type definitions are not installed by default.
1931 'unknown' is one of them. Install the "Special Generic Terminal
1932 Definitions" to make them defined.
1936 We list bugs in current versions here. See also the section on legacy
1939 *** On Solaris, C-x doesn't get through to Emacs when you use the console.
1941 This is a Solaris feature (at least on Intel x86 cpus). Type C-r
1942 C-r C-t, to toggle whether C-x gets through to Emacs.
1944 *** Problem with remote X server on Suns.
1946 On a Sun, running Emacs on one machine with the X server on another
1947 may not work if you have used the unshared system libraries. This
1948 is because the unshared libraries fail to use YP for host name lookup.
1949 As a result, the host name you specify may not be recognized.
1951 *** Solaris 2.6: Emacs crashes with SIGBUS or SIGSEGV on Solaris after you delete a frame.
1953 We suspect that this is a bug in the X libraries provided by
1954 Sun. There is a report that one of these patches fixes the bug and
1955 makes the problem stop:
1957 105216-01 105393-01 105518-01 105621-01 105665-01 105615-02 105216-02
1958 105667-01 105401-08 105615-03 105621-02 105686-02 105736-01 105755-03
1959 106033-01 105379-01 105786-01 105181-04 105379-03 105786-04 105845-01
1960 105284-05 105669-02 105837-01 105837-02 105558-01 106125-02 105407-01
1962 Another person using a newer system (kernel patch level Generic_105181-06)
1963 suspects that the bug was fixed by one of these more recent patches:
1965 106040-07 SunOS 5.6: X Input & Output Method patch
1966 106222-01 OpenWindows 3.6: filemgr (ff.core) fixes
1967 105284-12 Motif 1.2.7: sparc Runtime library patch
1969 *** Solaris 7 or 8: Emacs reports a BadAtom error (from X)
1971 This happens when Emacs was built on some other version of Solaris.
1972 Rebuild it on Solaris 8.
1974 *** When using M-x dbx with the SparcWorks debugger, the 'up' and 'down'
1975 commands do not move the arrow in Emacs.
1977 You can fix this by adding the following line to '~/.dbxinit':
1979 dbxenv output_short_file_name off
1981 *** On Solaris, CTRL-t is ignored by Emacs when you use
1982 the fr.ISO-8859-15 locale (and maybe other related locales).
1984 You can fix this by editing the file:
1986 /usr/openwin/lib/locale/iso8859-15/Compose
1988 Near the bottom there is a line that reads:
1990 Ctrl<t> <quotedbl> <Y> : "\276" threequarters
1992 while it should read:
1994 Ctrl<T> <quotedbl> <Y> : "\276" threequarters
1996 Note the lower case <t>. Changing this line should make C-t work.
1998 *** On Solaris, Emacs fails to set menu-bar-update-hook on startup, with error
1999 "Error in menu-bar-update-hook: (error Point before start of properties)".
2000 This seems to be a GCC optimization bug that occurs for GCC 4.1.2 (-g
2001 and -g -O2) and GCC 4.2.3 (-g -O and -g -O2). You can fix this by
2002 compiling with GCC 4.2.3 or CC 5.7, with no optimizations.
2004 * Runtime problems specific to MS-Windows
2006 ** Emacs on Windows 9X requires UNICOWS.DLL
2008 If that DLL is not available, Emacs will display an error dialog
2009 stating its absence, and refuse to run.
2011 This is because Emacs 24.4 and later uses functions whose non-stub
2012 implementation is only available in UNICOWS.DLL, which implements the
2013 Microsoft Layer for Unicode on Windows 9X, or "MSLU". This article on
2016 http://msdn.microsoft.com/en-us/goglobal/bb688166.aspx
2018 includes a short description of MSLU and a link where it can be
2021 ** Emacs refuses to start on Windows 9X because ctime64 function is missing
2023 This is a sign that Emacs was compiled with MinGW runtime version
2024 4.0.x or later. These versions of runtime call in their startup code
2025 the ctime64 function, which does not exist in MSVCRT.DLL, the C
2026 runtime shared library, distributed with Windows 9X.
2028 A workaround is to build Emacs with MinGW runtime 3.x (the latest
2031 ** addpm fails to run on Windows NT4, complaining about Shell32.dll
2033 This is likely to happen because Shell32.dll shipped with NT4 lacks
2034 the updates required by Emacs. Installing Internet Explorer 4 solves
2035 the problem. Note that it is NOT enough to install IE6, because doing
2036 so will not install the Shell32.dll update.
2038 ** A few seconds delay is seen at startup and for many file operations
2040 This happens when the Net Logon service is enabled. During Emacs
2041 startup, this service issues many DNS requests looking up for the
2042 Windows Domain Controller. When Emacs accesses files on networked
2043 drives, it automatically logs on the user into those drives, which
2044 again causes delays when Net Logon is running.
2046 The solution seems to be to disable Net Logon with this command typed
2047 at the Windows shell prompt:
2051 To start the service again, type "net start netlogon". (You can also
2052 stop and start the service from the Computer Management application,
2053 accessible by right-clicking "My Computer" or "Computer", selecting
2054 "Manage", then clicking on "Services".)
2056 ** Emacs crashes when exiting the Emacs session
2058 This was reported to happen when some optional DLLs, such as those
2059 used for displaying images or the GnuTLS library or zlib compression
2060 library, which are loaded on-demand, have a runtime dependency on the
2061 libgcc DLL, libgcc_s_dw2-1.dll. The reason seems to be a bug in
2062 libgcc which rears its ugly head whenever the libgcc DLL is loaded
2063 after Emacs has started.
2065 One solution for this problem is to find an alternative build of the
2066 same optional library that does not depend on the libgcc DLL.
2068 Another possibility is to rebuild Emacs with the -shared-libgcc
2069 switch, which will force Emacs to load libgcc_s_dw2-1.dll on startup,
2070 ahead of any optional DLLs loaded on-demand later in the session.
2072 ** File selection dialog opens in incorrect directories
2074 Invoking the file selection dialog on Windows 7 or later shows a
2075 directory that is different from what was passed to 'read-file-name'
2076 or 'x-file-dialog' via their arguments.
2078 This is due to a deliberate change in behavior of the file selection
2079 dialogs introduced in Windows 7. It is explicitly described in the
2080 MSDN documentation of the GetOpenFileName API used by Emacs to pop up
2081 the file selection dialog. For the details, see
2083 http://msdn.microsoft.com/en-us/library/windows/desktop/ms646839%28v=vs.85%29.aspx
2085 The dialog shows the last directory in which the user selected a file
2086 in a previous invocation of the dialog with the same initial
2089 You can reset this "memory" of that directory by invoking the file
2090 selection dialog with a different initial directory.
2092 ** PATH can contain unexpanded environment variables
2094 Old releases of TCC (version 9) and 4NT (up to version 8) do not correctly
2095 expand App Paths entries of type REG_EXPAND_SZ. When Emacs is run from TCC
2096 and such an entry exists for emacs.exe, exec-path will contain the
2097 unexpanded entry. This has been fixed in TCC 10. For more information,
2100 ** Setting w32-pass-rwindow-to-system and w32-pass-lwindow-to-system to nil
2101 does not prevent the Start menu from popping up when the left or right
2102 "Windows" key is pressed.
2104 This was reported to happen when XKeymacs is installed. At least with
2105 XKeymacs Version 3.47, deactivating XKeymacs when Emacs is active is
2106 not enough to avoid its messing with the keyboard input. Exiting
2107 XKeymacs completely is reported to solve the problem.
2109 ** Pasting from Windows clipboard into Emacs doesn't work.
2111 This was reported to be the result of an anti-virus software blocking
2112 the clipboard-related operations when a Web browser is open, for
2113 security reasons. The solution is to close the Web browser while
2114 working in Emacs, or to add emacs.exe to the list of applications that
2115 are allowed to use the clipboard when the Web browser is open.
2117 ** "Pinning" Emacs to the taskbar doesn't work on Windows 10
2119 "Doesn't work" here means that if you invoke Emacs by clicking on the
2120 pinned icon, a separate button appears on the taskbar, instead of the
2121 expected effect of the icon you clicked on being converted to that
2124 This is due to a bug in early versions of Windows 10, reportedly fixed
2125 in build 1511 of Windows 10 (a.k.a. "Windows 10 SP1"). If you cannot
2126 upgrade, read the work-around described below.
2128 First, be sure to edit the Properties of the pinned icon to invoke
2129 runemacs.exe, not emacs.exe. (The latter will cause an extra cmd
2130 window to appear when you invoke Emacs from the pinned icon.)
2132 But the real cause of the problem is the fact that the pinned icon
2133 (which is really a shortcut in a special directory) lacks a unique
2134 application-defined Application User Model ID (AppUserModelID) that
2135 identifies the current process to the taskbar. This identifier allows
2136 an application to group its associated processes and windows under a
2137 single taskbar button. Emacs on Windows specifies a unique
2138 AppUserModelID when it starts, but Windows 10, unlike previous
2139 versions of MS-Windows, does not propagate that ID to the pinned icon.
2141 To work around this, use some utility, such as 'win7appid', to set the
2142 AppUserModelID of the pinned icon to the string "Gnu.Emacs". The
2143 shortcut files corresponding to icons you pinned are stored by Windows
2144 in the following subdirectory of your user's directory (by default
2145 C:\Users\<UserName>\):
2147 AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar
2149 Look for the file 'emacs.lnk' there.
2151 ** Windows 95 and networking.
2153 To support server sockets, Emacs loads ws2_32.dll. If this file is
2154 missing, all Emacs networking features are disabled.
2156 Old versions of Windows 95 may not have the required DLL. To use
2157 Emacs's networking features on Windows 95, you must install the
2158 "Windows Socket 2" update available from MicroSoft's support Web.
2160 ** Emacs exits with "X protocol error" when run with an X server for MS-Windows.
2162 A certain X server for Windows had a bug which caused this.
2163 Supposedly the newer 32-bit version of this server doesn't have the
2166 ** Emacs crashes when opening a file with a UNC path and rails-mode is loaded.
2168 Loading rails-mode seems to interfere with UNC path handling. This has been
2169 reported as a bug against both Emacs and rails-mode, so look for an updated
2170 rails-mode that avoids this crash, or avoid using UNC paths if using
2173 ** M-x term does not work on MS-Windows.
2175 TTY emulation on Windows is undocumented, and programs such as stty
2176 which are used on POSIX platforms to control tty emulation do not
2177 exist for native windows terminals.
2179 ** Using create-fontset-from-ascii-font or the --font startup parameter
2180 with a Chinese, Japanese or Korean font leads to display problems.
2181 Use a Latin-only font as your default font. If you want control over
2182 which font is used to display Chinese, Japanese or Korean character,
2183 use create-fontset-from-fontset-spec to define a fontset.
2185 ** Frames are not refreshed while dialogs or menus are displayed
2187 This means no redisplay while the File or Font dialog or a pop-up menu
2188 is displayed. This also means tooltips with help text for pop-up
2189 menus are not displayed at all (except in a TTY session, where the help
2190 text is shown in the echo area). This is because message handling
2191 under Windows is synchronous, so we cannot handle repaint (or any
2192 other) messages while waiting for a system function, which popped up
2193 the menu/dialog, to return the result of the dialog or pop-up menu
2196 ** Help text in tooltips does not work on old Windows versions
2198 Windows 95 and Windows NT up to version 4.0 do not support help text
2199 for menus. Help text is only available in later versions of Windows.
2201 ** Display problems with ClearType method of smoothing
2203 When "ClearType" method is selected as the "method to smooth edges of
2204 screen fonts" (in Display Properties, Appearance tab, under
2205 "Effects"), there are various problems related to display of
2206 characters: Bold fonts can be hard to read, small portions of some
2207 characters could appear chopped, etc. This happens because, under
2208 ClearType, characters are drawn outside their advertised bounding box.
2209 Emacs 21 disabled the use of ClearType, whereas Emacs 22 allows it and
2210 has some code to enlarge the width of the bounding box. Apparently,
2211 this display feature needs more changes to get it 100% right. A
2212 workaround is to disable ClearType.
2214 ** Cursor is displayed as a thin vertical bar and cannot be changed
2216 This is known to happen if the Windows Magnifier is turned on before
2217 the Emacs session starts. The Magnifier affects the cursor shape and
2218 prevents any changes to it by setting the 'cursor-type' variable or
2221 The solution is to log off and on again, and then start the Emacs
2222 session only after turning the Magnifier off.
2224 To turn the Windows Magnifier off, click "Start->All Programs", or
2225 "All Apps", depending on your Windows version, then select
2226 "Accessibility" and click "Magnifier". In the Magnifier Settings
2227 dialog that opens, click "Exit".
2229 ** Problems with mouse-tracking and focus management
2231 There are problems with display if mouse-tracking is enabled and the
2232 mouse is moved off a frame, over another frame then back over the first
2233 frame. A workaround is to click the left mouse button inside the frame
2234 after moving back into it.
2236 Some minor flickering still persists during mouse-tracking, although
2237 not as severely as in 21.1.
2239 An inactive cursor remains in an active window after the Windows
2240 Manager driven switch of the focus, until a key is pressed.
2242 ** Problems with Windows input methods
2244 Some of the Windows input methods cause the keyboard to send
2245 characters encoded in the appropriate coding system (e.g., ISO 8859-1
2246 for Latin-1 characters, ISO 8859-8 for Hebrew characters, etc.). To
2247 make these input methods work with Emacs on Windows 9X, you might need
2248 to set the keyboard coding system to the appropriate value after you
2249 activate the Windows input method. For example, if you activate the
2250 Hebrew input method, type this:
2252 C-x RET k hebrew-iso-8bit RET
2254 In addition, to use these Windows input methods, you might need to set
2255 your "Language for non-Unicode programs" (on Windows XP, this is on
2256 the Advanced tab of Regional Settings) to the language of the input
2259 To bind keys that produce non-ASCII characters with modifiers, you
2260 must specify raw byte codes. For instance, if you want to bind
2261 META-a-grave to a command, you need to specify this in your '~/.emacs':
2263 (global-set-key [?\M-\340] ...)
2265 The above example is for the Latin-1 environment where the byte code
2266 of the encoded a-grave is 340 octal. For other environments, use the
2267 encoding appropriate to that environment.
2269 ** Problems with the %b format specifier for format-time-string
2271 The %b specifier for format-time-string does not produce abbreviated
2272 month names with consistent widths for some locales on some versions
2273 of Windows. This is caused by a deficiency in the underlying system
2276 ** Non-US time zones.
2278 Many non-US time zones are implemented incorrectly. This is due to
2279 over-simplistic handling of daylight savings switchovers by the
2282 ** Files larger than 4GB report wrong size in a 32-bit Windows build
2284 Files larger than 4GB cause overflow in the size (represented as a
2285 32-bit integer) reported by 'file-attributes'. This affects Dired as
2286 well, since the Windows port uses a Lisp emulation of 'ls', which relies
2287 on 'file-attributes'.
2289 ** Playing sound doesn't support the :data method
2291 Sound playing is not supported with the ':data DATA' key-value pair.
2292 You _must_ use the ':file FILE' method.
2294 ** Typing Alt-Shift has strange effects on MS-Windows.
2296 This combination of keys is a command to change keyboard layout. If
2297 you proceed to type another non-modifier key before you let go of Alt
2298 and Shift, the Alt and Shift act as modifiers in the usual way. A
2299 more permanent work around is to change it to another key combination,
2300 or disable it in the "Regional and Language Options" applet of the
2301 Control Panel. (The exact sequence of mouse clicks in the "Regional
2302 and Language Options" applet needed to find the key combination that
2303 changes the keyboard layout depends on your Windows version; for XP,
2304 in the Languages tab, click "Details" and then "Key Settings".)
2306 ** Interrupting Cygwin port of Bash from Emacs doesn't work.
2308 Cygwin 1.x builds of the ported Bash cannot be interrupted from the
2309 MS-Windows version of Emacs. This is due to some change in the Bash
2310 port or in the Cygwin library which apparently make Bash ignore the
2311 keyboard interrupt event sent by Emacs to Bash. (Older Cygwin ports
2312 of Bash, up to b20.1, did receive SIGINT from Emacs.)
2314 ** Accessing remote files with ange-ftp hangs the MS-Windows version of Emacs.
2316 If the FTP client is the Cygwin port of GNU 'ftp', this appears to be
2317 due to some bug in the Cygwin DLL or some incompatibility between it
2318 and the implementation of asynchronous subprocesses in the Windows
2319 port of Emacs. Specifically, some parts of the FTP server responses
2320 are not flushed out, apparently due to buffering issues, which
2323 The solution is to downgrade to an older version of the Cygwin DLL
2324 (version 1.3.2 was reported to solve the problem), or use the stock
2325 Windows FTP client, usually found in the 'C:\WINDOWS' or 'C:\WINNT'
2326 directory. To force ange-ftp use the stock Windows client, set the
2327 variable 'ange-ftp-ftp-program-name' to the absolute file name of the
2328 client's executable. For example:
2330 (setq ange-ftp-ftp-program-name "c:/windows/ftp.exe")
2332 If you want to stick with the Cygwin FTP client, you can work around
2333 this problem by putting this in your '.emacs' file:
2335 (setq ange-ftp-ftp-program-args '("-i" "-n" "-g" "-v" "--prompt" "")
2337 ** lpr commands don't work on MS-Windows with some cheap printers.
2339 This problem may also strike other platforms, but the solution is
2340 likely to be a global one, and not Emacs specific.
2342 Many cheap inkjet, and even some cheap laser printers, do not
2343 print plain text anymore, they will only print through graphical
2344 printer drivers. A workaround on MS-Windows is to use Windows's basic
2345 built in editor to print (this is possibly the only useful purpose it
2348 (setq printer-name "") ; notepad takes the default
2349 (setq lpr-command "notepad") ; notepad
2350 (setq lpr-switches nil) ; not needed
2351 (setq lpr-printer-switch "/P") ; run notepad as batch printer
2353 ** Antivirus software interacts badly with the MS-Windows version of Emacs.
2355 The usual manifestation of these problems is that subprocesses don't
2356 work or even wedge the entire system. In particular, "M-x shell RET"
2357 was reported to fail to work. But other commands also sometimes don't
2358 work when an antivirus package is installed.
2360 The solution is to switch the antivirus software to a less aggressive
2361 mode (e.g., disable the "auto-protect" feature), or even uninstall
2362 or disable it entirely.
2364 ** Pressing the mouse button on MS-Windows does not give a mouse-2 event.
2366 This is usually a problem with the mouse driver. Because most Windows
2367 programs do not do anything useful with the middle mouse button, many
2368 mouse drivers allow you to define the wheel press to do something
2369 different. Some drivers do not even have the option to generate a
2370 middle button press. In such cases, setting the wheel press to
2371 "scroll" sometimes works if you press the button twice. Trying a
2372 generic mouse driver might help.
2374 ** Scrolling the mouse wheel on MS-Windows always scrolls the top window.
2376 This is another common problem with mouse drivers. Instead of
2377 generating scroll events, some mouse drivers try to fake scroll bar
2378 movement. But they are not intelligent enough to handle multiple
2379 scroll bars within a frame. Trying a generic mouse driver might help.
2381 ** Mail sent through Microsoft Exchange in some encodings appears to be
2382 mangled and is not seen correctly in Rmail or Gnus. We don't know
2383 exactly what happens, but it isn't an Emacs problem in cases we've
2386 ** On MS-Windows, you cannot use the right-hand ALT key and the left-hand
2387 CTRL key together to type a Control-Meta character.
2389 This is a consequence of a misfeature beyond Emacs's control.
2391 Under Windows, the AltGr key on international keyboards generates key
2392 events with the modifiers Right-Alt and Left-Ctrl. Since Emacs cannot
2393 distinguish AltGr from an explicit Right-Alt and Left-Ctrl
2394 combination, whenever it sees Right-Alt and Left-Ctrl it assumes that
2395 AltGr has been pressed. The variable 'w32-recognize-altgr' can be set
2396 to nil to tell Emacs that AltGr is really Ctrl and Alt.
2398 ** Under some X-servers running on MS-Windows, Emacs's display is incorrect.
2400 The symptoms are that Emacs does not completely erase blank areas of the
2401 screen during scrolling or some other screen operations (e.g., selective
2402 display or when killing a region). M-x recenter will cause the screen
2403 to be completely redisplayed and the "extra" characters will disappear.
2405 This is known to occur under Exceed 6, and possibly earlier versions
2406 as well; it is reportedly solved in version 6.2.0.16 and later. The
2407 problem lies in the X-server settings.
2409 There are reports that you can solve the problem with Exceed by
2410 running 'Xconfig' from within NT, choosing "X selection", then
2411 un-checking the boxes "auto-copy X selection" and "auto-paste to X
2414 If this does not work, please inform bug-gnu-emacs@gnu.org. Then
2415 please call support for your X-server and see if you can get a fix.
2416 If you do, please send it to bug-gnu-emacs@gnu.org so we can list it here.
2419 * Runtime problems specific to Mac OS X
2421 ** On Mac OS X, file-name-case-insensitive-p may be unreliable
2423 The implementation of that function on Mac OS X uses pathconf with the
2424 _PC_CASE_SENSITIVE flag. There have been reports that this use of
2425 pathconf does not work reliably. If you have a problem, please
2426 recompile Emacs with -D DARWIN_OS_CASE_SENSITIVE_FIXME=1 or
2427 -D DARWIN_OS_CASE_SENSITIVE_FIXME=2, and file a bug report saying
2428 whether this fixed your problem.
2430 * Build-time problems
2434 *** 'configure' warns "accepted by the compiler, rejected by the preprocessor".
2436 This indicates a mismatch between the C compiler and preprocessor that
2437 configure is using. For example, on Solaris 10 trying to use
2438 CC=/opt/SUNWspro/bin/cc (the Sun Studio compiler) together with
2439 CPP=/usr/ccs/lib/cpp can result in errors of this form (you may also
2440 see the error '"/usr/include/sys/isa_defs.h", line 500: undefined control').
2442 The solution is to tell configure to use the correct C preprocessor
2443 for your C compiler (CPP="/opt/SUNWspro/bin/cc -E" in the above
2448 *** Building Emacs over NFS fails with "Text file busy".
2450 This was reported to happen when building Emacs on a GNU/Linux system
2451 (Red Hat Linux 6.2) using a build directory automounted from Solaris
2452 (SunOS 5.6) file server, but it might not be limited to that
2453 configuration alone. Presumably, the NFS server doesn't commit the
2454 files' data to disk quickly enough, and the Emacs executable file is
2455 left "busy" for several seconds after Emacs has finished dumping
2456 itself. This causes the subsequent commands which invoke the dumped
2457 Emacs executable to fail with the above message.
2459 In some of these cases, a time skew between the NFS server and the
2460 machine where Emacs is built is detected and reported by GNU Make
2461 (it says that some of the files have modification time in the future).
2462 This might be a symptom of NFS-related problems.
2464 If the NFS server runs on Solaris, apply the Solaris patch 105379-05
2465 (Sunos 5.6: /kernel/misc/nfssrv patch). If that doesn't work, or if
2466 you have a different version of the OS or the NFS server, you can
2467 force the NFS server to use 1KB blocks, which was reported to fix the
2468 problem albeit at a price of slowing down file I/O. You can force 1KB
2469 blocks by specifying the "-o rsize=1024,wsize=1024" options to the
2470 'mount' command, or by adding ",rsize=1024,wsize=1024" to the mount
2471 options in the appropriate system configuration file, such as
2474 Alternatively, when Make fails due to this problem, you could wait for
2475 a few seconds and then invoke Make again. In one particular case,
2476 waiting for 10 or more seconds between the two Make invocations seemed
2477 to work around the problem.
2479 Similar problems can happen if your machine NFS-mounts a directory
2480 onto itself. Suppose the Emacs sources live in '/usr/local/src' and
2481 you are working on the host called 'marvin'. Then an entry in the
2482 '/etc/fstab' file like the following is asking for trouble:
2484 marvin:/usr/local/src /usr/local/src ...options.omitted...
2486 The solution is to remove this line from '/etc/fstab'.
2488 *** Building a 32-bit executable on a 64-bit GNU/Linux architecture.
2490 First ensure that the necessary 32-bit system libraries and include
2491 files are installed. Then use:
2493 env CC="gcc -m32" ./configure --build=i386-linux-gnu --x-libraries=/usr/lib
2495 (using the location of the 32-bit X libraries on your system).
2497 *** Building on FreeBSD 11 fails at link time due to unresolved symbol
2499 The symbol is sendmmsg@FBSD_1.4. This is due to a faulty libgio
2500 library on these systems. The solution is to reconfigure Emacs while
2501 disabling all the features that require libgio: rsvg, dbus, gconf, and
2504 *** Building Emacs for Cygwin can fail with GCC 3
2506 As of Emacs 22.1, there have been stability problems with Cygwin
2507 builds of Emacs using GCC 3. Cygwin users are advised to use GCC 4.
2509 *** Building Emacs 23.3 and later will fail under Cygwin 1.5.19
2511 This is a consequence of a change to src/dired.c on 2010-07-27. The
2512 issue is that Cygwin 1.5.19 did not have d_ino in 'struct dirent'.
2515 http://lists.gnu.org/archive/html/emacs-devel/2010-07/msg01266.html
2517 *** Building the native MS-Windows port fails due to unresolved externals
2519 The linker error messages look like this:
2521 oo-spd/i386/ctags.o:ctags.c:(.text+0x156e): undefined reference to `_imp__re_set_syntax'
2522 collect2: ld returned 1 exit status
2524 This happens because GCC finds an incompatible regex.h header
2525 somewhere on the include path, before the version of regex.h supplied
2526 with Emacs. One such incompatible version of regex.h is part of the
2527 GnuWin32 Regex package.
2529 The solution is to remove the incompatible regex.h from the include
2530 path, when compiling Emacs. Alternatively, re-run the configure.bat
2531 script with the "-isystem C:/GnuWin32/include" switch (adapt for your
2532 system's place where you keep the GnuWin32 include files) -- this will
2533 cause the compiler to search headers in the directories specified by
2534 the Emacs Makefile _before_ it looks in the GnuWin32 include
2537 *** Building the native MS-Windows port with Cygwin GCC can fail.
2539 Emacs may not build using some Cygwin builds of GCC, such as Cygwin
2540 version 1.1.8, using the default configure settings. It appears to be
2541 necessary to specify the -mwin32 flag when compiling, and define
2542 __MSVCRT__, like so:
2544 configure --with-gcc --cflags -mwin32 --cflags -D__MSVCRT__
2546 *** Building the MS-Windows port fails with a CreateProcess failure.
2548 Some versions of mingw32 make on some versions of Windows do not seem
2549 to detect the shell correctly. Try "make SHELL=cmd.exe", or if that
2550 fails, try running make from Cygwin bash instead.
2552 *** Building 'ctags' for MS-Windows with the MinGW port of GCC fails.
2554 This might happen due to a bug in the MinGW header assert.h, which
2555 defines the 'assert' macro with a trailing semi-colon. The following
2556 patch to assert.h should solve this:
2558 *** include/assert.h.orig Sun Nov 7 02:41:36 1999
2559 --- include/assert.h Mon Jan 29 11:49:10 2001
2563 * If not debugging, assert does nothing.
2565 ! #define assert(x) ((void)0);
2567 #else /* debugging enabled */
2571 * If not debugging, assert does nothing.
2573 ! #define assert(x) ((void)0)
2575 #else /* debugging enabled */
2578 *** Building the MS-Windows port with Visual Studio 2005 fails.
2580 Microsoft no longer ships the single threaded version of the C library
2581 with their compiler, and the multithreaded static library is missing
2582 some functions that Microsoft have deemed non-threadsafe. The
2583 dynamically linked C library has all the functions, but there is a
2584 conflict between the versions of malloc in the DLL and in Emacs, which
2585 is not resolvable due to the way Windows does dynamic linking.
2587 We recommend the use of the MinGW port of GCC for compiling Emacs, as
2588 not only does it not suffer these problems, but it is also Free
2589 software like Emacs.
2591 *** Building the MS-Windows port with Visual Studio fails compiling emacs.rc
2593 If the build fails with the following message then the problem
2594 described here most likely applies:
2596 ../nt/emacs.rc(1) : error RC2176 : old DIB in icons\emacs.ico; pass it
2599 The Emacs icon contains a high resolution PNG icon for Vista, which is
2600 not recognized by older versions of the resource compiler. There are
2601 several workarounds for this problem:
2602 1. Use Free MinGW tools to compile, which do not have this problem.
2603 2. Install the latest Windows SDK.
2604 3. Replace emacs.ico with an older or edited icon.
2606 *** Building the MS-Windows port complains about unknown escape sequences.
2608 Errors and warnings can look like this:
2610 w32.c:1959:27: error: \x used with no following hex digits
2611 w32.c:1959:27: warning: unknown escape sequence '\i'
2613 This happens when paths using backslashes are passed to the compiler or
2614 linker (via -I and possibly other compiler flags); when these paths are
2615 included in source code, the backslashes are interpreted as escape sequences.
2616 See http://lists.gnu.org/archive/html/emacs-devel/2010-07/msg00995.html
2618 The fix is to use forward slashes in all paths passed to the compiler.
2622 *** Building Emacs with a system compiler fails to link because of an
2623 undefined symbol such as __eprintf which does not appear in Emacs.
2625 This can happen if some of the libraries linked into Emacs were built
2626 with GCC, but Emacs itself is being linked with a compiler other than
2627 GCC. Object files compiled with GCC might need some helper functions
2628 from libgcc.a, the library which comes with GCC, but the system
2629 compiler does not instruct the linker to search libgcc.a during the
2632 A solution is to link with GCC, like this:
2636 Since the .o object files already exist, this will not recompile Emacs
2637 with GCC, but just restart by trying again to link temacs.
2639 *** Sun with acc: Link failure when using acc on a Sun.
2641 To use acc, you need additional options just before the libraries, such as
2643 /usr/lang/SC2.0.1/values-Xt.o -L/usr/lang/SC2.0.1/cg87 -L/usr/lang/SC2.0.1
2645 and you need to add -lansi just before -lc.
2647 The precise file names depend on the compiler version, so we
2648 cannot easily arrange to supply them.
2650 *** 'tparam' reported as a multiply-defined symbol when linking with ncurses.
2652 This problem results from an incompatible change in ncurses, in
2653 version 1.9.9e approximately. This version is unable to provide a
2654 definition of tparm without also defining tparam. This is also
2655 incompatible with Terminfo; as a result, the Emacs Terminfo support
2656 does not work with this version of ncurses.
2658 The fix is to install a newer version of ncurses, such as version 4.2.
2662 Bootstrapping (compiling the .el files) is normally only necessary
2663 with development builds, since the .elc files are pre-compiled in releases.
2665 *** "No rule to make target" with Ubuntu 8.04 make 3.81-3build1
2667 Compiling the lisp files fails at random places, complaining:
2668 "No rule to make target '/path/to/some/lisp.elc'".
2669 The causes of this problem are not understood. Using GNU make 3.81 compiled
2670 from source, rather than the Ubuntu version, worked.
2671 See <URL:http://debbugs.gnu.org/327>, <URL:http://debbugs.gnu.org/821>.
2675 *** Segfault during 'make'
2677 If Emacs segfaults when 'make' executes one of these commands:
2679 LC_ALL=C ./temacs -batch -l loadup bootstrap
2680 LC_ALL=C ./temacs -batch -l loadup dump
2682 the problem may be due to inadequate workarounds for address space
2683 layout randomization (ASLR), an operating system feature that
2684 randomizes the virtual address space of a process. ASLR is commonly
2685 enabled in Linux and NetBSD kernels, and is intended to deter exploits
2686 of pointer-related bugs in applications. If ASLR is enabled, the
2689 cat /proc/sys/kernel/randomize_va_space # GNU/Linux
2690 sysctl security.pax.aslr.global # NetBSD
2692 outputs a nonzero value.
2694 These segfaults should not occur on most modern systems, because the
2695 Emacs build procedure uses the command 'setfattr' or 'paxctl' to mark
2696 the Emacs executable as requiring non-randomized address space, and
2697 Emacs uses the 'personality' system call to disable address space
2698 randomization when dumping. However, older kernels may not support
2699 'setfattr', 'paxctl', or 'personality', and newer Linux kernels have a
2700 secure computing mode (seccomp) that can be configured to disable the
2703 It may be possible to work around the 'personality' problem in a newer
2704 Linux kernel by configuring seccomp to allow the 'personality' call.
2705 For example, if you are building Emacs under Docker, you can run the
2706 Docker container with a security profile that allows 'personality' by
2707 using Docker's --security-opt option with an appropriate profile; see
2708 <https://docs.docker.com/engine/security/seccomp/>.
2710 To work around the ASLR problem in either an older or a newer kernel,
2711 you can temporarily disable the feature while building Emacs. On
2712 GNU/Linux you can do so using the following command (as root).
2714 echo 0 > /proc/sys/kernel/randomize_va_space
2716 You can re-enable the feature when you are done, by echoing the
2717 original value back to the file. NetBSD uses a different command,
2718 e.g., 'sysctl -w security.pax.aslr.global=0'.
2720 Alternatively, you can try using the 'setarch' command when building
2721 temacs like this, where -R disables address space randomization:
2723 setarch $(uname -m) -R make
2725 ASLR is not the only problem that can break Emacs dumping. Another
2726 issue is that in Red Hat Linux kernels, Exec-shield is enabled by
2727 default, and this creates a different memory layout. Emacs should
2728 handle this at build time, but if this fails the following
2729 instructions may be useful. Exec-shield is enabled on your system if
2731 cat /proc/sys/kernel/exec-shield
2733 prints a nonzero value. You can temporarily disable it as follows:
2735 echo 0 > /proc/sys/kernel/exec-shield
2737 As with randomize_va_space, you can re-enable Exec-shield when you are
2738 done, by echoing the original value back to the file.
2740 *** temacs prints "Pure Lisp storage exhausted".
2742 This means that the Lisp code loaded from the .elc and .el files during
2743 'temacs --batch --load loadup dump' took up more space than was allocated.
2745 This could be caused by
2746 1) adding code to the preloaded Lisp files
2747 2) adding more preloaded files in loadup.el
2748 3) having a site-init.el or site-load.el which loads files.
2749 Note that ANY site-init.el or site-load.el is nonstandard;
2750 if you have received Emacs from some other site and it contains a
2751 site-init.el or site-load.el file, consider deleting that file.
2752 4) getting the wrong .el or .elc files
2753 (not from the directory you expected).
2754 5) deleting some .elc files that are supposed to exist.
2755 This would cause the source files (.el files) to be
2756 loaded instead. They take up more room, so you lose.
2757 6) a bug in the Emacs distribution which underestimates the space required.
2759 If the need for more space is legitimate, change the definition
2760 of PURESIZE in puresize.h.
2762 But in some of the cases listed above, this problem is a consequence
2763 of something else that is wrong. Be sure to check and fix the real problem.
2765 *** OpenBSD 4.0 macppc: Segfault during dumping.
2767 The build aborts with signal 11 when the command './temacs --batch
2768 --load loadup bootstrap' tries to load files.el. A workaround seems
2769 to be to reduce the level of compiler optimization used during the
2770 build (from -O2 to -O1). It is possible this is an OpenBSD
2771 GCC problem specific to the macppc architecture, possibly only
2772 occurring with older versions of GCC (e.g. 3.3.5).
2774 *** openSUSE 10.3: Segfault in bcopy during dumping.
2776 This is due to a bug in the bcopy implementation in openSUSE 10.3.
2777 It is/will be fixed in an openSUSE update.
2781 *** Emacs binary is not in executable format, and cannot be run.
2783 This was reported to happen when Emacs is built in a directory mounted
2784 via NFS, for some combinations of NFS client and NFS server.
2785 Usually, the file 'emacs' produced in these cases is full of
2786 binary null characters, and the 'file' utility says:
2788 emacs: ASCII text, with no line terminators
2790 We don't know what exactly causes this failure. A work-around is to
2791 build Emacs in a directory on a local disk.
2793 *** The dumped Emacs crashes when run, trying to write pure data.
2795 On a system where getpagesize is not a system call, it is defined
2796 as a macro. If the definition (in both unex*.c and malloc.c) is wrong,
2797 it can cause problems like this. You might be able to find the correct
2798 value in the man page for a.out(5).
2800 * Problems on legacy systems
2802 This section covers bugs reported on very old hardware or software.
2803 If you are using hardware and an operating system shipped after 2000,
2804 it is unlikely you will see any of these.
2808 **** Strange results from format %d in a few cases, on a Sun.
2810 Sun compiler version SC3.0 has been found to miscompile part of editfns.c.
2811 The workaround is to compile with some other compiler such as GCC.
2813 **** On Solaris, Emacs dumps core if lisp-complete-symbol is called.
2815 If you compile Emacs with the -fast or -xO4 option with version 3.0.2
2816 of the Sun C compiler, Emacs dumps core when lisp-complete-symbol is
2817 called. The problem does not happen if you compile with GCC.
2819 **** On Solaris, Emacs crashes if you use (display-time).
2821 This can happen if you configure Emacs without specifying the precise
2822 version of Solaris that you are using.
2824 **** Solaris 2.x: GCC complains "64 bit integer types not supported".
2826 This suggests that GCC is not installed correctly. Most likely you
2827 are using GCC 2.7.2.3 (or earlier) on Solaris 2.6 (or later); this
2828 does not work without patching. To run GCC 2.7.2.3 on Solaris 2.6 or
2829 later, you must patch fixinc.svr4 and reinstall GCC from scratch as
2830 described in the Solaris FAQ
2831 <http://www.wins.uva.nl/pub/solaris/solaris2.html>. A better fix is
2832 to upgrade to GCC 2.8.1 or later.
2834 **** Solaris 2.7: Building Emacs with WorkShop Compilers 5.0 98/12/15
2835 C 5.0 failed, apparently with non-default CFLAGS, most probably due to
2836 compiler bugs. Using Sun Solaris 2.7 Sun WorkShop 6 update 1 C
2837 release was reported to work without problems. It worked OK on
2838 another system with Solaris 8 using apparently the same 5.0 compiler
2839 and the default CFLAGS.
2841 **** Solaris 2.x: Emacs dumps core when built with Motif.
2843 The Solaris Motif libraries are buggy, at least up through Solaris 2.5.1.
2844 Install the current Motif runtime library patch appropriate for your host.
2845 (Make sure the patch is current; some older patch versions still have the bug.)
2846 You should install the other patches recommended by Sun for your host, too.
2847 You can obtain Sun patches from ftp://sunsolve.sun.com/pub/patches/;
2848 look for files with names ending in '.PatchReport' to see which patches
2849 are currently recommended for your host.
2851 On Solaris 2.6, Emacs is said to work with Motif when Solaris patch
2852 105284-12 is installed, but fail when 105284-15 is installed.
2853 105284-18 might fix it again.
2855 **** Solaris 2.6 and 7: the Compose key does not work.
2857 This is a bug in Motif in Solaris. Supposedly it has been fixed for
2858 the next major release of Solaris. However, if someone with Sun
2859 support complains to Sun about the bug, they may release a patch.
2860 If you do this, mention Sun bug #4188711.
2862 One workaround is to use a locale that allows non-ASCII characters.
2863 For example, before invoking emacs, set the LC_ALL environment
2864 variable to "en_US" (American English). The directory /usr/lib/locale
2865 lists the supported locales; any locale other than "C" or "POSIX"
2868 pen@lysator.liu.se says (Feb 1998) that the Compose key does work
2869 if you link with the MIT X11 libraries instead of the Solaris X11 libraries.
2871 ** MS-Windows 95, 98, ME, and NT
2873 *** MS-Windows NT/95: Problems running Perl under Emacs
2875 'perl -de 0' just hangs when executed in an Emacs subshell.
2876 The fault lies with Perl (indirectly with Windows NT/95).
2878 The problem is that the Perl debugger explicitly opens a connection to
2879 "CON", which is the DOS/NT equivalent of "/dev/tty", for interacting
2882 On Unix, this is okay, because Emacs (or the shell?) creates a
2883 pseudo-tty so that /dev/tty is really the pipe Emacs is using to
2884 communicate with the subprocess.
2886 On NT, this fails because CON always refers to the handle for the
2887 relevant console (approximately equivalent to a tty), and cannot be
2888 redirected to refer to the pipe Emacs assigned to the subprocess as
2891 A workaround is to modify perldb.pl to use STDIN/STDOUT instead of CON.
2895 *** PERL/LIB/PERLDB.PL.orig Wed May 26 08:24:18 1993
2896 --- PERL/LIB/PERLDB.PL Mon Jul 01 15:28:16 1996
2903 $rcfile="perldb.ini";
2911 $rcfile="perldb.ini";
2916 *** perl/5.001/lib/perl5db.pl.orig Sun Jun 04 21:13:40 1995
2917 --- perl/5.001/lib/perl5db.pl Mon Jul 01 17:00:08 1996
2924 $rcfile="perldb.ini";
2932 $rcfile="perldb.ini";
2936 *** MS-Windows 95: Alt-f6 does not get through to Emacs.
2938 This character seems to be trapped by the kernel in Windows 95.
2939 You can enter M-f6 by typing ESC f6.
2941 *** MS-Windows 95/98/ME: subprocesses do not terminate properly.
2943 This is a limitation of the Operating System, and can cause problems
2944 when shutting down Windows. Ensure that all subprocesses are exited
2945 cleanly before exiting Emacs. For more details, see the Emacs on MS
2946 Windows FAQ (info manual "efaq-w32").
2948 *** MS-Windows 95/98/ME: crashes when Emacs invokes non-existent programs.
2950 When a program you are trying to run is not found on the PATH,
2951 Windows might respond by crashing or locking up your system. In
2952 particular, this has been reported when trying to compile a Java
2953 program in JDEE when javac.exe is installed, but not on the system PATH.
2957 *** When compiling with DJGPP on MS-Windows NT or later, "config msdos" fails.
2959 If the error message is "VDM has been already loaded", this is because
2960 Windows has a program called 'redir.exe' that is incompatible with a
2961 program by the same name supplied with DJGPP, which is used by
2962 config.bat. To resolve this, move the DJGPP's 'bin' subdirectory to
2963 the front of your PATH environment variable.
2965 *** When Emacs compiled with DJGPP runs on Windows 2000 and later, it cannot
2966 find your HOME directory.
2968 This was reported to happen when you click on "Save for future
2969 sessions" button in a Customize buffer. You might see an error
2970 message like this one:
2972 basic-save-buffer-2: c:/FOO/BAR/~dosuser/: no such directory
2974 (The telltale sign is the "~USER" part at the end of the directory
2975 Emacs complains about, where USER is your username or the literal
2976 string "dosuser", which is the default username set up by the DJGPP
2977 startup file DJGPP.ENV.)
2979 This happens when the functions 'user-login-name' and
2980 'user-real-login-name' return different strings for your username as
2981 Emacs sees it. To correct this, make sure both USER and USERNAME
2982 environment variables are set to the same value. Windows 2000 and
2983 later sets USERNAME, so if you want to keep that, make sure USER is
2984 set to the same value. If you don't want to set USER globally, you
2985 can do it in the [emacs] section of your DJGPP.ENV file.
2987 *** When Emacs compiled with DJGPP runs on Vista, it runs out of memory.
2989 If Emacs running on Vista displays "!MEM FULL!" in the mode line, you
2990 are hitting the memory allocation bugs in the Vista DPMI server. See
2991 msdos/INSTALL for how to work around these bugs (search for "Vista").
2993 *** When compiling with DJGPP on MS-Windows 95, Make fails for some targets
2996 This can happen if long file name support (the setting of environment
2997 variable LFN) when Emacs distribution was unpacked and during
2998 compilation are not the same. See msdos/INSTALL for the explanation
2999 of how to avoid this problem.
3001 *** Emacs compiled with DJGPP complains at startup:
3003 "Wrong type of argument: internal-facep, msdos-menu-active-face"
3005 This can happen if you define an environment variable 'TERM'. Emacs
3006 on MSDOS uses an internal terminal emulator which is disabled if the
3007 value of 'TERM' is anything but the string "internal". Emacs then
3008 works as if its terminal were a dumb glass teletype that doesn't
3009 support faces. To work around this, arrange for 'TERM' to be
3010 undefined when Emacs runs. The best way to do that is to add an
3011 [emacs] section to the DJGPP.ENV file which defines an empty value for
3012 'TERM'; this way, only Emacs gets the empty value, while the rest of
3013 your system works as before.
3015 *** MS-DOS: Emacs crashes at startup.
3017 Some users report that Emacs 19.29 requires dpmi memory management,
3018 and crashes on startup if the system does not have it. We don't
3019 know why this happens--perhaps these machines don't have enough real
3020 memory, or perhaps something is wrong in Emacs or the compiler.
3021 However, arranging to use dpmi support is a workaround.
3023 You can find out if you have a dpmi host by running go32 without
3024 arguments; it will tell you if it uses dpmi memory. For more
3025 information about dpmi memory, consult the djgpp FAQ. (djgpp
3026 is the GNU C compiler as packaged for MSDOS.)
3028 Compiling Emacs under MSDOS is extremely sensitive for proper memory
3029 configuration. If you experience problems during compilation, consider
3030 removing some or all memory resident programs (notably disk caches)
3031 and make sure that your memory managers are properly configured. See
3032 the djgpp faq for configuration hints.
3034 *** Emacs compiled with DJGPP for MS-DOS/MS-Windows cannot access files
3035 in the directory with the special name 'dev' under the root of any
3036 drive, e.g. 'c:/dev'.
3038 This is an unfortunate side-effect of the support for Unix-style
3039 device names such as /dev/null in the DJGPP runtime library. A
3040 work-around is to rename the problem directory to another name.
3042 *** MS-DOS: Emacs compiled for MSDOS cannot find some Lisp files, or other
3043 run-time support files, when long filename support is enabled.
3045 Usually, this problem will manifest itself when Emacs exits
3046 immediately after flashing the startup screen, because it cannot find
3047 the Lisp files it needs to load at startup. Redirect Emacs stdout
3048 and stderr to a file to see the error message printed by Emacs.
3050 Another manifestation of this problem is that Emacs is unable to load
3051 the support for editing program sources in languages such as C and Lisp.
3053 This can happen if the Emacs distribution was unzipped without LFN
3054 support, thus causing long filenames to be truncated to the first 6
3055 characters and a numeric tail that Windows 95 normally attaches to it.
3056 You should unzip the files again with a utility that supports long
3057 filenames (such as djtar from DJGPP or InfoZip's UnZip program
3058 compiled with DJGPP v2). The file msdos/INSTALL explains this issue
3061 Another possible reason for such failures is that Emacs compiled for
3062 MSDOS is used on Windows NT, where long file names are not supported
3063 by this version of Emacs, but the distribution was unpacked by an
3064 unzip program that preserved the long file names instead of truncating
3065 them to DOS 8+3 limits. To be useful on NT, the MSDOS port of Emacs
3066 must be unzipped by a DOS utility, so that long file names are
3069 ** Archaic window managers and toolkits
3071 *** Open Look: Under Open Look, the Emacs window disappears when you type M-q.
3073 Some versions of the Open Look window manager interpret M-q as a quit
3074 command for whatever window you are typing at. If you want to use
3075 Emacs with that window manager, you should try to configure the window
3076 manager to use some other command. You can disable the
3077 shortcut keys entirely by adding this line to ~/.OWdefaults:
3079 OpenWindows.WindowMenuAccelerators: False
3081 *** twm: A position you specified in .Xdefaults is ignored, using twm.
3083 twm normally ignores "program-specified" positions.
3084 You can tell it to obey them with this command in your '.twmrc' file:
3086 UsePPosition "on" #allow clients to request a position
3088 ** Bugs related to old DEC hardware
3090 *** The Compose key on a DEC keyboard does not work as Meta key.
3092 This shell command should fix it:
3094 xmodmap -e 'keycode 0xb1 = Meta_L'
3096 *** Keyboard input gets confused after a beep when using a DECserver
3099 This problem seems to be a matter of configuring the DECserver to use
3100 7 bit characters rather than 8 bit characters.
3102 This file is part of GNU Emacs.
3104 GNU Emacs is free software: you can redistribute it and/or modify
3105 it under the terms of the GNU General Public License as published by
3106 the Free Software Foundation, either version 3 of the License, or
3107 (at your option) any later version.
3109 GNU Emacs is distributed in the hope that it will be useful,
3110 but WITHOUT ANY WARRANTY; without even the implied warranty of
3111 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3112 GNU General Public License for more details.
3114 You should have received a copy of the GNU General Public License
3115 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
3120 paragraph-separate: "[
\f]*$"