Debugging in Qt Creator 3.1.0 does not work (GDB on linux)

I recently upgraded from Qt Creator from version 3.0 to 3.1.0. in this version I was not able to debug any programs anymore.
When I start debugging I get this output:

Debugging starts
&"warning: GDB: Failed to set controlling terminal: Inappropriate ioctl for device\n"

The application runs, but it is not debugging. After a while I get a message window that says:

The gdb process has not responded to a command within 40 second(s). This could mean it is stuck in an endless loop or taking longer than expected to perform the operation.
You can choose between waiting longer or aborting debugging.

I also can't kill the application with the stop button in Qt Creator when debugging.