1 .. _environment_variables:
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4 Environment Variables Impacting the Build System
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7 Various environment variables have an impact on the behavior of the
8 build system. This document attempts to document them.
11 If defines, the build system will automatically clobber as needed.
12 The default behavior is to print a message and error out when a
15 This variable is typically defined in a :ref:`mozconfig <mozconfig>`
16 file via ``mk_add_options``.
19 If defined, the build system will print information about why
20 certain files were rebuilt.
22 This feature is disabled by default because it makes the build slower.
24 MACH_NO_TERMINAL_FOOTER
25 If defined, the terminal footer displayed when building with mach in
29 If defined, mach commands will not prefix output lines with the
30 elapsed time since program start. This option is equivalent to
31 passing ``--log-no-times`` to mach.