Problem on compiling a Qt project on Linux

[mrdebug]

I trying to compile a project but I'm obtaining this error:

usr/include/c++/4.9/bits/stl_relops.:67: Parse error at "std"
Makefile:324: set di istruzioni per l'obiettivo "moc_qfmainwindow.cpp" non riuscito
make: *** [moc_qfmainwindow.cpp] Errore 1

Does someone know what it means and how to resolve?

[Ni.Sumi]

@mrdebug

It's an error from you pro file and the path give to C++/4.9. May be an extra '/''s or wrong path. Check the INCLUDEPATH + = in the pro file.

[mrdebug]

Solved by removing the file qmake.stash