I'm getting the following output on my arch linux machine running latest qt-creator v3.6.1:
[e@m4500 QtCreatorCoveragePlugin]$ qmake -r
Reading /home/e/QtCreatorCoveragePlugin/src/src.pro
Reading /home/e/QtCreatorCoveragePlugin/src/lib/lib.pro
Project ERROR: QTC_PLUGIN_NAME is empty. Maybe you meant to create lib_dependencies.pri?
Won't let me run make after...