Rhythmbox crashes in source_rhythmbox.py during apport reporting of a bug

Description: Ubuntu 15.04
Release: 15.04

rhythmbox:
  Installed: 3.1-1ubuntu3
  Candidate: 3.1-1ubuntu3
  Version table:
 *** 3.1-1ubuntu3 0
        500 http://gb.archive.ubuntu.com/ubuntu/ vivid/main amd64 Packages
        100 /var/lib/dpkg/status

I expect to be prompted to report a bug during a crash, instead nothing happens.
The crash report in /var/crash/_usr_lib_rhythmbox_rhythmbox-metadata.500.upload is zero bytes
In $HOME/.cache/upstart/ I have file update-notifier-crash-_var_crash__usr_lib_rhythmbox_rhythmbox-metadata.500.crash.log.1.gz attached