Faulty Makefiles produced by qmake on Beta2

When trying to build any .pro file I am getting an error message from g++ that there is no file or directory.

holger@hmpf:~/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/examples/qtbase/animation/animatedtiles$ ../../../../bin/qmake
holger@hmpf:~/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/examples/qtbase/animation/animatedtiles$ make
/home/holger/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/bin/moc -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../../../mkspecs/linux-g++-64 -I. -I../../../../include -I../../../../include/QtWidgets -I../../../../include/QtGui -I../../../../include/QtCore -I. main.cpp -o main.moc
g++ -c -m64 -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../../../mkspecs/linux-g++-64 -I. -I../../../../include -I../../../../include/QtWidgets -I../../../../include/QtGui -I../../../../include/QtCore -I. -o main.o main.cpp
/home/holger/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/bin/rcc -name animatedtiles animatedtiles.qrc -o qrc_animatedtiles.cpp
g++ -c -m64 -pipe -O2 -Wall -W -D_REENTRANT -fPIE -DQT_NO_DEBUG -DQT_WIDGETS_LIB -DQT_GUI_LIB -DQT_CORE_LIB -I../../../../mkspecs/linux-g++-64 -I. -I../../../../include -I../../../../include/QtWidgets -I../../../../include/QtGui -I../../../../include/QtCore -I. -o qrc_animatedtiles.o qrc_animatedtiles.cpp
g++ -m64 -Wl,-O1 -Wl,-rpath,/home/holger/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/examples/qtbase/animation/animatedtiles/_____________________________PADDING_____________________________ -Wl,-rpath,/home/holger/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/lib -o animatedtiles main.o qrc_animatedtiles.o -L/usr/X11R6/lib64 -L/home/holger/Betas/Qt5.0.0beta2/5.0.0-beta2/gcc_64/lib -lQtWidgets b -lQtGui -lQtCore -lGL -lpthread
g++: error: b: No such file or directory
make: *** [animatedtiles] Error 1

This happens with everything I try to compile. The Problem is with the "b" in the Library Loading.