ubiquity crashed with NameError in progress_loop()

Cutout from /var/log/syslog that seems relevant:

Jan 21 15:36:06 ubuntu os-prober: debug: running /usr/lib/os-probes/50mounted-tests on /dev/sda7
Jan 21 15:36:06 ubuntu 50mounted-tests: debug: /dev/sda7 is a swap partition; skipping
Jan 21 15:36:06 ubuntu os-prober: debug: os detected by /usr/lib/os-probes/50mounted-tests
Jan 21 15:36:06 ubuntu migration-assistant: info: setting ostype from: '/dev/sda1:Microsoft Windows XP Professional:Windows:chain'
Jan 21 15:36:06 ubuntu migration-assistant: info: got ostype of: 'windowsxp', mountpoint is: '/mnt/migrationassistant'
Jan 21 15:36:07 ubuntu ntfs-3g[15801]: Version 2009.4.4 external FUSE 27
Jan 21 15:36:07 ubuntu ntfs-3g[15801]: Mounted /dev/sda1 (Read-Write, label "", NTFS 3.1)
Jan 21 15:36:07 ubuntu ntfs-3g[15801]: Cmdline options: rw,umask=0022,nls=utf8
Jan 21 15:36:07 ubuntu ntfs-3g[15801]: Mount options: rw,nls=utf8,silent,allow_other,nonempty,default_permissions,relatime,fsname=/dev/sda1,blkdev,blksize=4096
profilesdir: /mnt/migrationassistant/Documents and Settings
profilesdir: /mnt/migrationassistant/Documents and Settings
Jan 21 15:36:08 ubuntu ntfs-3g[15801]: Unmounting /dev/sda1 ()
Jan 21 15:36:08 ubuntu ubiquity[5026]: switched to page migrationassistant
Jan 21 15:36:10 ubuntu ubiquity[5026]: debconffilter_done: ubiquity.components.migrationassistant (current: ubiquity.components.migrationassistant)
Jan 21 15:36:10 ubuntu ubiquity[5026]: Step_before = stepMigrationAssistant
Jan 21 15:36:10 ubuntu ubiquity[5026]: switched to page summary
Jan 21 15:36:16 ubuntu ubiquity[5026]: debconffilter_done: ubiquity.components.summary (current: ubiquity.components.summary)
Jan 21 15:36:16 ubuntu ubiquity[5026]: Step_before = stepReady
Jan 21 15:36:16 ubuntu ubiquity[5026]: progress_loop()
Jan 21 15:36:16 ubuntu ubiquity[5026]: Exception in GTK frontend (invoking crash handler):
Jan 21 15:36:16 ubuntu ubiquity[5026]: Traceback (most recent call last):
Jan 21 15:36:16 ubuntu ubiquity[5026]: File "/usr/lib/ubiquity/bin/ubiquity", line 450, in <module>
Jan 21 15:36:16 ubuntu ubiquity[5026]: main(oem_config)
Jan 21 15:36:16 ubuntu ubiquity[5026]: File "/usr/lib/ubiquity/bin/ubiquity", line 435, in main
Jan 21 15:36:16 ubuntu ubiquity[5026]: install(args[0], query=options.query)
Jan 21 15:36:16 ubuntu ubiquity[5026]: File "/usr/lib/ubiquity/bin/ubiquity", line 243, in install
Jan 21 15:36:16 ubuntu ubiquity[5026]: ret = wizard.run()
Jan 21 15:36:16 ubuntu ubiquity[5026]: File "/usr/lib/ubiquity/ubiquity/frontend/gtk_ui.py", line 512, in run
Jan 21 15:36:16 ubuntu ubiquity[5026]: self.progress_loop()
Jan 21 15:36:16 ubuntu ubiquity[5026]: File "/usr/lib/ubiquity/ubiquity/frontend/gtk_ui.py", line 952, in progress_loop
Jan 21 15:36:16 ubuntu ubiquity[5026]: slideshow_locale = slideshow_get_available_locale(slideshow_dir, self.locale)
Jan 21 15:36:16 ubuntu ubiquity[5026]: NameError: global name 'slideshow_get_available_locale' is not defined
Jan 21 15:36:16 ubuntu ubiquity[5026]:
Jan 21 15:36:30 ubuntu wpa_supplicant[2020]: CTRL-EVENT-SCAN-RESULTS
Jan 21 15:37:30 ubuntu wpa_supplicant[2020]: CTRL-EVENT-SCAN-RESULTS
Jan 21 15:38:30 ubuntu wpa_supplicant[2020]: CTRL-EVEN...

Confirmed on the latest UNR daily

This bug was fixed in the package ubiquity - 2.1.13

---------------
ubiquity (2.1.13) lucid; urgency=low

  [ Colin Watson ]
  * Don't crash if something races with ubiquity or ubiquity-dm to create
    /var/log/installer (LP: #458806).

  [ Evan Dandrea ]
  * Support the new translated keyboard names in console-setup
    (LP: #127528).
  * Provide an option to determine the keymap from a decision tree.
  * Add missing parameter to exception in bin/ubiquity.
  * slideshow_get_available_locale is an instance method (LP: #510710).
  * The frontend always has a db attribute, per r3665, so revise the check in
    debconf_communicator. Thanks Colin Watson.
  * Add missing function argument to Install's prepare.
  * Automatic update of included source packages: console-setup
    1.34ubuntu7, grub-installer 1.49ubuntu2, partman-uboot 3.

  [ Mario Limonciello ]
  * Remove another reference to a long dead xserver-xorg debconf question.
  * Don't try reconfiguring LRM, it's been superceded by DKMS based packages.
 -- Evan Dandrea <email address hidden> Fri, 22 Jan 2010 09:24:12 +0000