clang tidy emits errors about exceptions being disabled when the are enabled

I enabled clang-tidy integration to a CMake project like so:

set(CMAKE_CXX_CLANG_TIDY 
  clang-tidy;
  -header-filter=.;
  --config-file=${MY_CLANG_TIDY_CONFIG_PATH};
)

In the .clang-tidy config file, there are rules for checking naming conventions only.

After generating the project and trying to build one one of the targets, I get an error from clang claiming exceptions are used even though disabled.

This is the command I run and its output:

cmake --build --preset=ninja-wd --target=Eureka.Core

output:

[1/3] Building CXX object Libs\Eureka.Core\CMakeFiles\Eureka.Core.dir\system.cpp.obj
FAILED: Libs/Eureka.Core/CMakeFiles/Eureka.Core.dir/system.cpp.obj
"C:\Program Files\CMake\bin\cmake.exe" -E __run_co_compile --tidy=clang-tidy;-header-filter=.;--config-file=C:/workspace/Eureka/.clang-tidy;--extra-arg-before=--driver-mode=cl --source=C:\workspace\Eureka\Libs\Eureka.Core\system.cpp -- C:\PROGRA~1\MICROS~222\COMMUN~1\VC\Tools\MSVC34~1.319\bin\Hostx64\x64\cl.exe  /nologo /TP -DBoost_NO_WARN_NEW_VERSIONS=1 -DEUREKA_NO_NVTOOLSEXT -DNOMINMAX -DPERFETTO_TRACING -DPROFILING_ENABLED -DWIN32_LEAN_AND_MEAN -IC:\workspace\Eureka -IC:\workspace\Eureka\Libs\Eureka.Core /DWIN32 /D_WINDOWS /EHsc /Zi /Ob0 /Od /RTC1 -MDd /permissive- /bigobj /W4 /EHsc -std:c++latest /showIncludes /FoLibs\Eureka.Core\CMakeFiles\Eureka.Core.dir\system.cpp.obj /FdLibs\Eureka.Core\CMakeFiles\Eureka.Core.dir\Eureka.Core.pdb /FS -c C:\workspace\Eureka\Libs\Eureka.Core\system.cpp
C:\workspace\Eureka\Libs\Eureka.Core\system.cpp:26:9: error: cannot use 'throw' with exceptions disabled [clang-diagnostic-error]
        throw std::system_error(ec, "system error");
        ^
2823 warnings and 1 error generated.
Error while processing C:\workspace\Eureka\Libs\Eureka.Core\system.cpp.
Suppressed 2824 warnings (2823 in non-user code, 1 NOLINT).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
Found compiler error(s).

As far as I can see, the /EHsc flag is passed to cl.exe. And yet I get the error from clang saying

error: cannot use 'throw' with exceptions disabled [clang-diagnostic-error]
            throw std::system_error(ec, "system error");

What is going on here? why is clang-tidy complaining?

If I disable the clang-tidy integration, the project builds just fine.

Seems that clang-tidy fails to recognize the /EHsc after -- (the parameters given to cl.exe).

You may try manually add a --extra-args=/EHsc into your CMAKE_CXX_CLANG_TIDY to bypass that issue.

https://gitlab.kitware.com/cmake/cmake/-/issues/20512 possibly the issue.