CMake/Help/policy/CMP0132.rst

CMP0132
-------

.. versionadded:: 3.24

Do not set compiler environment variables on first run.

Apart from when using the :generator:`Xcode` generator and some :ref:`Visual
Studio Generators`, CMake 3.23 and below will set environment variables like
:envvar:`CC`, :envvar:`CXX`, etc. when the corresponding language is enabled.
This only occurs on the very first time CMake is run in a build directory,
and the environment variables are only defined at configure time, not build
time. On subsequent CMake runs, these environment variables are not set,
opening up the opportunity for different behavior between the first and
subsequent CMake runs. CMake 3.24 and above prefer to not set these
environment variables when a language is enabled, even on the first run in
a build directory.

The ``OLD`` behavior for this policy sets the relevant environment variable
on the first run when a language is enabled. The ``NEW`` behavior for this
policy does not set any such environment variables.

.. |INTRODUCED_IN_CMAKE_VERSION| replace:: 3.24
.. |WARNS_OR_DOES_NOT_WARN| replace:: does *not* warn
.. include:: include/STANDARD_ADVICE.rst

.. include:: include/DEPRECATED.rst