CMake Error at bad-DIRECTORY\.cmake:[0-9]+ \(file\):
  Error evaluating generator expression:

    \$<SOURCE_EXISTS:foo\.c,DIRECTORY:foo>

  Directory.+".+/Tests/RunCMake/GenEx-SOURCE_EXISTS/foo".+is.+not.+known.+from.+CMake\.
Call Stack \(most recent call first\):
  CMakeLists\.txt:[0-9]+ \(include\)
