VS: CMake unity build triggers msbuild warning MSB8027 "Two or more files with the name of filename will produce outputs to the same location."
Nothing too serious but an eye-catching warning here.
When unity build are enabled, Object File Name is set to $(IntDir) in Visual Studio so all obj files are written in the same folder.
No one is stepping on anyone's toes here, unity build files have unique filenames (unity_0_cxx.cxx, unity_1_cxx.cxx, etc) and are compiled into unique obj files (unity_0_cxx.obj, unity_1_cxx.obj, etc)
But for practical reasons, individual cpp files are also kept in the project (because we want to edit them), and are still marked as 'compilable' (useful when doing some refactoring imho, I like to be able to compile a standalone cpp file without having to disable ub)
Seeing this, msbuild triggers a legitimate warning MSB8027 "Two or more files with the name of filename will produce outputs to the same location." as soon as two files in the same project have identical names (ex: folderA/file.cpp and folderB/file.cpp). But no big deal here because they won't be compiled when the lib is built, only if we manually compile them.