$ cmake ..
[...]
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
CMake Error in /home/mc/vxsort-cpp/build/CMakeFiles/CMakeTmp/CMakeLists.txt:
  Target "cmTC_9bed8" requires the language dialect "C14" (with compiler
  extensions).  But the current compiler "Clang" does not support this, or
  CMake does not know the flags to enable it.


CMake Error at /usr/share/cmake/Modules/Internal/CheckSourceCompiles.cmake:95 (try_compile):
  Failed to generate test project build system.
Call Stack (most recent call first):
  /usr/share/cmake/Modules/CheckCSourceCompiles.cmake:76 (cmake_check_source_compiles)
  /usr/share/cmake/Modules/FindThreads.cmake:163 (CHECK_C_SOURCE_COMPILES)
  build/googlebenchmark-src/CMakeLists.txt:293 (find_package)


-- Configuring incomplete, errors occurred!
See also "/home/mc/vxsort-cpp/build/CMakeFiles/CMakeOutput.log".
See also "/home/mc/vxsort-cpp/build/CMakeFiles/CMakeError.log".

Performing C++ SOURCE FILE Test HAVE_CXX_FLAG_WD654 failed with the following output:
Change Dir: /home/mc/vxsort-cpp/build/CMakeFiles/CMakeTmp

Run Build Command(s):/usr/bin/make -f Makefile cmTC_541d6/fast && /usr/bin/make  -f CMakeFiles/cmTC_541d6.dir/build.make CMakeFiles/cmTC_541d6.dir/build
make[1]: Entering directory '/home/mc/vxsort-cpp/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_541d6.dir/src.cxx.o
/usr/bin/clang++ -DHAVE_CXX_FLAG_WD654  -std=c++11  -Wall  -Wextra  -Wshadow  -Wsuggest-override  -pedantic  -pedantic-errors  -Wshorten-64-to-32  -fstrict-aliasing  -Wno-deprecated-declarations  -Wstrict-aliasing  -wd654   -wd654 -std=gnu++14 -MD -MT CMakeFiles/cmTC_541d6.dir/src.cxx.o -MF CMakeFiles/cmTC_541d6.dir/src.cxx.o.d -o CMakeFiles/cmTC_541d6.dir/src.cxx.o -c /home/mc/vxsort-cpp/build/CMakeFiles/CMakeTmp/src.cxx
clang-13: error: unknown argument: '-wd654'
clang-13: error: unknown argument: '-wd654'
make[1]: *** [CMakeFiles/cmTC_541d6.dir/build.make:79: CMakeFiles/cmTC_541d6.dir/src.cxx.o] Error 1
make[1]: Leaving directory '/home/mc/vxsort-cpp/build/CMakeFiles/CMakeTmp'
make: *** [Makefile:127: cmTC_541d6/fast] Error 2


Source file was:
int main() { return 0; }