How to fix this error : searching for unused variables given on the command line. -- The C compiler identification is unknown CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE): No CMAKE_C_COMPILER could be found. Tell CMake w

Question

I have Visual Studio 2022 installed and I have set environmental variables for C compiler but I still get the error ;
How do I locate the CMakeLists.txt file to amend line 3 as thats where the error is coming from?

 searching for unused variables given on the command line.
      -- The C compiler identification is unknown
      CMake Error at CMakeLists.txt:3 (ENABLE_LANGUAGE):
        No CMAKE_C_COMPILER could be found.

        Tell CMake where to find the compiler by setting either the environment
        variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to
        the compiler, or to the compiler name if it is in the PATH.

Answer 1

Hello @Jude Oyedele ,

Welcome to Microsoft Q&A forum.

Does installing a new Windows SDK work(VS Installer => Modify => Individual components => SDKs, libraries, and frameworks)?

Besides, does this issue also appear on a newly created CMake project in Visual Studio? If it is reproducible, please share us the detailed steps to reproduce it and check further.

Best Regards,

Tianyu

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Answer 2

What later works was running the intended installation command, which is pip install langflow via the x64 Native tool Command Prompt for VScode.
It successfully built the wheel for llama-cpp-python which was the initial cause of the error.