viz, gannotate, gmissing peg CPU at 100%

[Selene ToyKeeper]

Whenever I use the viz tool, bzr eats up an entire CPU core as long as it's running. I also see this with bzr gannotate and bzr gmissing. But I don't see this behavior in gbranch, gcheckout, gcommit, gconflicts, gdiff, gmerge, gpreferences, gpush, gsend, gstatus, or gtags.

I did some quick attempts to profile the process to see where it's looping, but I didn't locate the cause of the issue. It looks like the pygtk C library may be where it gets stuck, but it's probably being triggered by something the python code does to set up the application.

   ncalls tottime percall cumtime percall filename:lineno(function)
        1 16.473 16.473 17.028 17.028 Gtk.py:1637(main)
      115 0.052 0.000 0.062 0.001 ui.py:28(with_main_iteration)
    11218 0.040 0.000 0.051 0.000 GObject.py:237(set_value)
       71 0.029 0.000 0.029 0.000 __init__.py:277(new_init)
    11218 0.029 0.000 0.030 0.000 GObject.py:220(__del__)
    11218 0.027 0.000 0.103 0.000 Gtk.py:918(_convert_value)
    11218 0.022 0.000 0.073 0.000 GObject.py:213(__init__)
       70 0.020 0.000 0.051 0.001 graphcell.py:153(do_render)

Just in case it might reveal something, I also tried adding a @q on pretty much every function and method in bzr-gtk, but the main CPU-eating loop doesn't seem to invoke anything easily visible while it's working.

I also see nothing happening in dbus-monitor while the CPU is pegged.

The packages I'm using are...

bzr 2.7.0+bzr6622-15
bzr-gtk https://code.launchpad.net/~bzr-gtk/bzr-gtk/trunk revno 797
python-gtk2 2.24.0-5.1+b1
python-gtksourceview2 2.10.1-2

Any idea what could be causing this?