Makefile warnings

I have suddenly started getting the following make warnings:

Makefile.Debug:137: warning: overriding commands for target `debug\moc_MainWindow.cpp'
Makefile.Debug:129: warning: ignoring old commands for target `debug\moc_MainWindow.cpp'
Makefile.Debug:226: warning: overriding commands for target `debug\moc_MainWindow.o'
Makefile.Debug:220: warning: ignoring old commands for target `debug\moc_MainWindow.o'

and the following errors:

./debug\moc_mainwindow.o(.text+0x100): In function `ZNK10MainWindow10metaObjectEv':
C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:97: multiple definition of `MainWindow::metaObject() const'
./debug\moc_MainWindow.o(.text+0x100):C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:97: first defined here
./debug\moc_mainwindow.o(.text+0x10a): In function `ZN10MainWindow11qt_metacastEPKc':
C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:102: multiple definition of `MainWindow::qt_metacast(char const*)'
./debug\moc_MainWindow.o(.text+0x10a):C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:102: first defined here
./debug\moc_mainwindow.o(.text+0x158): In function `ZN10MainWindow11qt_metacallEN11QMetaObject4CallEi PPv':
C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:110: multiple definition of `MainWindow::qt_metacall(QMetaObject::Call, int, void**)'
./debug\moc_MainWindow.o(.text+0x158):C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp:110: first defined here
./debug\moc_mainwindow.o(.data+0x0): In function `ZThn8_N10MainWindowD1Ev':
C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp: multiple definition of `MainWindow::staticMetaObject'
./debug\moc_MainWindow.o(.data+0x0):C:/Data/Qt/mverse/n1/debug/moc_mainwindow.cpp: first defined here

This happened after a 'qmake -project' 'qmake n1.pro' 'make'

I have tried undoing my changes but I must be overlooking something, they still show up.

Thanks
Doug Broadwell

P.S., this is in version 4.1.1

It looks like a header file has been added several time to the HEADERS variable... Check out the content of the pro file and remove any duplicated files. alternatively you can substitute operator "*=" to operator "+=". Thus qmake will itself ensure that each file is present only once...