SDL2.0.10 Static Library with CMake BROKEN

Hi there,
I’m on windows 10, using clang + mingw.
I recently attempted to update to sdl2.0.10. I invoke the following command:

cmake.exe -DCMAKE_BUILD_TYPE=Debug -G "MinGW Makefiles"^
        -DCMAKE_C_FLAGS="-target x86_64-windows-gnu"^
        -DCMAKE_C_COMPILER_ID="Clang" -DCMAKE_C_COMPILER="clang.exe"^
        -DCMAKE_CXX_FLAGS="-target x86_64-windows-gnu"^
        -DCMAKE_CXX_COMPILER_ID="Clang++" -DCMAKE_CXX_COMPILER="clang++.exe"^

cmake.exe --build . -- -j %NUMBER_OF_PROCESSORS%

This produces un-usable ‘.lib’ files, specifically SDL2maind.lib and SDL2d.lib. Performing the same invocation on sdl2.0.9 gives usable ‘.a’ files, specifically libSDL2maind.a and libSDL2d.a. If this is a problem, could someone give me a link to an archived sdl2.0.9 source?