cmake server-mode does not list header files from the source directory. See attached cmake-tutorial tar. I does show the header in headers/ but not the one in ./ – this is because https://github.com/qtproject/qt-creator/blob/master/src/plugins/cmakeprojectmanager/servermodereader.cpp#L692 does not contain the source directory itself, only the headers subdir.

I am not sure if this is a bug in qtc, cmake server-mode or my CMakeLists.txt. To the best of my knowledge, the source directory is path of the include path, even though I did not list it explicitly.