test_gdb currently fails on 3k; some tests with a "No stack" message. I'll attach the full output, but would like this issue to focus on the "No stack" failures.
The problem is that test_gdb is not compatible with Python3. test_gdb uses "print x" syntax instead of "print(x)", and "except XXX, xxx:" instead of "except XXX as xxx:". Note: "print range(1000)" => "print(list(range(1000)))". DebuggerOutput.run_gdb() should also convert the output to unicode, maybe using out = out.decode("ascii"); err = err.decode("ascii");.