The current regular expression is able to match `/usr/lib/<arch>`,
`/usr/usr/lib/<arch>`, `/usr/usr/usr/lib/<arch>`, ... but not
`/lib/<arch>`.
This behavior ends up causing the detected architecture to
be x86_64-pc-linux-gnu when the Clang compiler is installed on
a "non-system" location (like /opt/llvm-13) which, in turn, makes
almost every 'find_library()' fail because the correct
architecture is x86_64-linux-gnu.
This is due to a typo in commit 764606e256 (CMakeDetermineCompilerABI:
Extract lib arch from implicit object file paths, 2021-04-05,
v3.20.1~10^2), which used `+` instead of `?`.
CMake Tests Directory
*********************
This directory contains the CMake test suite.
See also the `CMake Source Code Guide`_.
.. _`CMake Source Code Guide`: ../Help/dev/source.rst
Many tests exist as immediate subdirectories, but some tests
are organized as follows.
* ``CMakeLib/``:
Source code, used for tests, that links to the ``CMakeLib`` library
defined over in ``Source/``.
* ``CMakeOnly/``:
Deprecated. Tests that run CMake to generate a project but not build it.
Superseded by ``Tests/RunCMake/``.
* ``Find*/``:
Tests for specific find modules that can only be run on machines with
the corresponding packages installed. They are enabled in
``CMakeLists.txt`` by undocumented options used on CI builds.
* ``Module/``:
Tests for specific CMake modules.
* ``RunCMake/``:
Tests that run CMake and/or other tools while precisely checking
their return code and stdout/stderr content. Useful for testing
error cases and diagnostic output.
Raphael Gozzo
d4ba945c48