Don't overuse "qmake -project". You should run it at most once, to create an initial .pro file for your project. If you call it later you can run into troubles as it scans directories recursively for any files that look like C++ sources.

Judging from the errors, it looks like your .pro file contains too much entries. Open it with a text editor and remove all automatically generated files from HEADERS and SOURCES variables. Then run "qmake" and "make".