Hi,
I manage to have it working by modifying the following lines in libs\openFrameworksCompiled\project\qtcreator\openFrameworks.qbs :
//line 110 was : var qbsCmd = new Command(product.make, ['Release','-j4']);
var qbsCmd = new Command("sh ", ['-c', 'make', 'Release','-j4']);
You should do the same with the Debug some lines above.
Hope it helps.