Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator'

[Marius Gedminas]

I tried to gdb a gnome-shell segfault:

(gdb) bt
#0 0x00007f8cad51f638 in g_slice_alloc (magazine_chunks=0xf879b0) at /build/buildd/glib2.0-2.44.0/./glib/gslice.c:535
#1 0x00007f8cad51f638 in g_slice_alloc (tmem=<optimized out>, ix=1) at /build/buildd/glib2.0-2.44.0/./glib/gslice.c:842
#2 0x00007f8cad51f638 in g_slice_alloc (mem_size=mem_size@entry=24) at /build/buildd/glib2.0-2.44.0/./glib/gslice.c:998
Python Exception <class 'TypeError'> iter() returned non-iterator of type '_iterator':

This looks like a bug in a gdb pretty-printer that's shipped with Ubuntu.

[Marius Gedminas (mgedmin)]

The command to list Python scripts that have been autoloaded is:

    (gdb) info auto-load python-scripts

I'm guessing /usr/share/gdb/auto-load/lib/x86_64-linux-gnu/libglib-2.0.so.0.4400.0-gdb.py is the one that causes my problem.
It's a small script that adds /usr/share/glib-2.0/gdb to sys.path and imports stuff from it.

/usr/share/glib-2.0/gdb is shipped in libglib2.0-0-dbg.

[Marius Gedminas (mgedmin)]

gdb in Ubuntu links against libpython3.4.

The Python scripts in /usr/share/glib-2.0/gdb haven't been fully ported to Python 3: the custom iterators should define a '__next__' method alias pointing to 'next'.

[Marius Gedminas (mgedmin)]

Somewhat-related upstream bug: https://bugzilla.gnome.org/show_bug.cgi?id=720635

[Marius Gedminas (mgedmin)]

Upstream bug with a patch: https://bugzilla.gnome.org/show_bug.cgi?id=749092

[Iain Lane (laney)]

Cheers - I think it'd be good to get this naturally via upstream. Do you agree? When the patch is acked, you can ask to have it put into the stable branch too & then we'll get it in vivid.