Use ghc return value instead of looking for the stderr, do not throw error when an haskell module throws a build failure, e.g. because of false positives like this one (debian/arm*) "You are using a new version of LLVM that hasn't been tested yet! We will try though..."

if(WIN32 AND NOT UNIX)
    file(GLOB DLLs *.dll)
    file(GLOB ICOs *.ico)

    install(FILES
        ${DLLs}
        ${ICOs}
        DESTINATION ${target_library_install_dir})
endif(WIN32 AND NOT UNIX)