Why vcpkg manifest mode not uses the CMAKE_C_COMPILER and CMAKE_CXX_COMPILER for dependency compilation?

[stripe2933]

I'm struggling for linking issue (ABI break) between GCC compiled vcpkg dependency and Clang compiled my own executable in ubuntu-latest (the problematic library is ktx), and it looks like many people are suffering for this issue. There is suggested solution for Windows system but I have no idea how to apply this into my environment.

But with more fundamental question is: why vcpkg manifest mode does not compile the dependencies with CMake provided compiler (CMAKE_C_COMPILER and CMAKE_CXX_COMPILER)? With same compiler, there would be no linking issue. I couldn't understand why they use the system default compiler for managing dependency.