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

    DATA{MissingData.txt}

  corresponds to source tree path

    MissingData.txt

  that does not exist as a file \(with or without an extension\)!
Call Stack \(most recent call first\):
  .*
  MissingData\.cmake:[0-9]+ \(ExternalData_Expand_Arguments\)
  CMakeLists\.txt:[0-9]+ \(include\)
This warning is for project developers.  Use -Wno-dev to suppress it.