As a followup to bug #175374:

The ability for cmake to be run in a "build" subdirectory is great, but I feel the default should be to do that; the checkbox to do that doesn't get checked if you don't go through the manual configuration process, and that makes it a teensy bit less usable for me [although the big thing has now been resolved, Huzzah!]

I suspect that the best thing to do is to make it do this by default for qmake and cmake, but not for configure. I have copious experience with badly behaved autoconf scripts that don't "do the right thing" for this, but cmake and qmake always seem to work perfectly.