QMAKESPEC is not set

I have tried to compile qtiplot for x64 tumbleweed, but since the QMAKESPEC is not set, qmake puts some libraries into /usr/lib instead of /usr/lib64. If I set the variable manually with “export QMAKESPEC=linux-g+±64” everything works fine, but I cannot do it on OBS.
The compilation works fine with the standard 12.3 version, and it has been working for Tumbleweed few days ago, too.
I have no idea, whether it is a bug in Tumbleweed or a new “feature” of qmake… :sarcastic:

Never mind, I’ve simply set the variable explicitly in the spec file using

%ifarch x86_64
export QMAKESPEC=linux-g++-64