When adding -binary flag to QMAKE_RESOURCE_FLAGS causes rcc to output a version of the generated cpp file which cannot be compiled due to some kind of error in nonprintable characters the top of the cpp file. A small extract of the many errors is as follows:

debug\qrc_resources.cpp:1:5: warning: null character(s) ignored [enabled by default]
qres
^
debug\qrc_resources.cpp:1:1: error: stray '\1' in program
qres

In addition, warnings over potential duplicate aliases detected are also shown, where the qrc file is known to be correct.