Today I tried to using the new qtcreator 4.1.0 rc1. It comes with qbs 1.6.0. And it version of qbs can't build my project, with next error message from moc -> ... stl_relops.:68: Parse error at "std". Despite the fact that qbs 1.5.0 build this project fine. I looked at the command lines that generate these versions of qbs and their differences. And saw that 1.6.0 (compared to 1.5.0) adds to the command line for additional paths to include files. The path which leads to the problem (in my casre it -IZ:/mingw/msys64/mingw32/include/c++/6.1.0) would add the following code in moc.js (in function args(product, input, outputFileName))

includePaths = includePaths.uniqueConcat(ModUtils.modulePropertiesFromArtifacts(product, [input], 'cpp', 'compilerIncludePaths'));

If try remove this code that the project is build fine.