> Can you try to get the Python traceback and/or C traceback using gdb?
Sry, I can't - I don't know how to use gdb :-(
Is there some one-line command which makes gdb start xvfb-run and attach to it? Or do I need to start xvfb-run and separately attach gdb to it? (how do I do this?)

> ... and hence would need xvfb-run on a headless server, as opposed to a workstation with screen.  Erich, I assume you are running on the latter.

I'm running this on a headless box (packaging for archlinux32). Setting up a desktop on the test box would be some effort, but should be possible in principle.

In the original PKGBUILD which Eli posted, there is a comment about when the tests started failing - which suggests, the problem is connected to xvfb-run.