Good idea. I think it may be possible for qmake to do this via the .pro file.
That would be better.
I looked through the documentation and an "undocumented qmake features" guide and couldn't find a good way. Even if I get the qmake file to error out, it still keeps trying to build it. I couldn't find an actual minimum version property, either. Is there a better place for me to start looking for this?
I was thinking a combination of http://qt-project.org/doc/qt-4.8/qmake-function-reference.html#error-string and what we do here might work.
If that's what you tried, perhaps there's a previous Makefile that already exists, and our builder just continues along regardless of the error returned by qmake? From the looks of CapybaraWebkitBuilder and the Rakefile, that should cause the build to fail, but maybe there's something I'm missing.
Fail immediately when trying to compile with less than Qt 4.8
* Add a Qt version assertion to main.cpp
* Move main.cpp to the top of the sources list so it compiles early
This was merged as f35e2df.