Qt Creator GDB version detection is broken, resulting in a broken debugging experience. For details, see:

http://www.mail-archive.com/mingw-w64-public@lists.sourceforge.net/msg07369.html

The crux of the matter is that

In the debugger log window it shows UNSUPPORTED GDB VERSION GNU gdb
(rubenvb-4.8.0) 7.5.91.20130322-cvs

Which means that the GDB version string parser does not take into account the (optional) pkgversion string, which toolchain distributors like myself use to allow users to provide clear version information when reporting problems.

This was not a problem in versions 2.6.* and below.