I narrowed down the ubiquity crash. It's apparently related to the custom widgets. If I update a live system to ppa:ubuntu-desktop/ppa, I get a proper crash with
PYTHONPATH=/usr/lib/ubiquity python
>>> from gi.repository import Gtk
>>> import ubiquity.gtkwidgets
>>> b = Gtk.Builder()
>>> b.add_from_file('/usr/share/ubiquity/gtk/stepPrepare.ui')
Segmentation fault (core dumped)
I narrowed down the ubiquity crash. It's apparently related to the custom widgets. If I update a live system to ppa:ubuntu- desktop/ ppa, I get a proper crash with
PYTHONPATH= /usr/lib/ ubiquity python file('/ usr/share/ ubiquity/ gtk/stepPrepare .ui')
>>> from gi.repository import Gtk
>>> import ubiquity.gtkwidgets
>>> b = Gtk.Builder()
>>> b.add_from_
Segmentation fault (core dumped)