CMake Error at target_sources.cmake:2 \(target_sources\):
  Error evaluating generator expression:

    \$<COMPILE_LANGUAGE>

  \$<COMPILE_LANGUAGE:...> may only be used to specify include directories,
  compile definitions, compile options, and to evaluate components of the
  file\(GENERATE\) command.
Call Stack \(most recent call first\):
  CMakeLists.txt:3 \(include\)