CMake Error at .*/Modules/ExternalData.cmake:[0-9]+ \(message\):
  Data directory referenced by argument

    DATA{Directory2/}

  must list associated files.
Call Stack \(most recent call first\):
  .*
  Directory2\.cmake:[0-9]+ \(ExternalData_Add_Test\)
  CMakeLists\.txt:[0-9]+ \(include\)
