Projects can't find assets when built using "Ninja Multi-config" CMake generator

[footballhead]

On both Linux and Windows:

$ cmake -B build -G "Ninja Multi-Config" .
$ cmake --build build --config Debug --target vk_sample_01_triangle
$ ./build/bin/Debug/vk_sample_01_triangle

...

*** PPX ASSERT ***
Message   : Could not determine asset path for "basic/shaders/spv/StaticVertexColors.vs.spv"
Condition : !assetPath.empty()
Function  : GetAssetPath
Location  : /usr/local/google/home/hitchens/git/bigwheels/src/ppx/base_application.cpp : 102

vk_sample_01_triangle: /usr/local/google/home/hitchens/git/bigwheels/src/ppx/base_application.cpp:102: std::filesystem::__cxx11::path ppx::BaseApplication::GetAssetPath(const std::filesystem::__cxx11::path&) const: Assertion `false' failed.

This works fine with the normal Ninja generator

[footballhead]

This works with the Visual Studio generator which requires the same config param....

It appears that RELATIVE_PATH_TO_PROJECT_ROOT is ..\.. with MSVC generator but .. with Ninja Multi-Config generator.

[footballhead]

RELATIVE_PATH_TO_PROJECT_ROOT is generated by CMakeLists.txt. That code has a hack for Visual Studio specifically:

cmake_path(SET BUILD_DIRECTORY NORMALIZE "${CMAKE_BINARY_DIR}")
if (CMAKE_GENERATOR MATCHES "Visual Studio")
    # Visual Studio doesn't follow CMAKE_RUNTIME_OUTPUT_DIRECTORY, but
    # creates a subdirectory with the config name.
    cmake_path(SET EXECUTABLE_DIRECTORY NORMALIZE "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/subfolder")
else ()
    cmake_path(SET EXECUTABLE_DIRECTORY NORMALIZE "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}")
endif ()
cmake_path(RELATIVE_PATH BUILD_DIRECTORY BASE_DIRECTORY ${EXECUTABLE_DIRECTORY} OUTPUT_VARIABLE BUILD_TO_EXECUTABLE_PATH)
add_compile_definitions(RELATIVE_PATH_TO_PROJECT_ROOT="${BUILD_TO_EXECUTABLE_PATH}")

There's a per-config CMAKE_RUNTIME_OUTPUT_DIRECTORY_<CONFIG>. That should be used instead to make this more generic