CMake Error at .*/Modules/CheckIncludeFiles.cmake:[0-9]+. \(message\):
  Unknown language:

    FOOBAR

  Supported languages: C, CXX.

Call Stack \(most recent call first\):
  CheckIncludeFilesUnknownLanguage.cmake:[0-9]+ \(check_include_files\)
  CMakeLists.txt:[0-9]+ \(include\)