Comment 2 for bug 729415

Exception during installation:
Mar 4 18:03:58 ubuntu python: Traceback (most recent call last):
Mar 4 18:03:58 ubuntu python: File "/usr/share/ubiquity/plugininstall.py", line 1424, in <module>
Mar 4 18:03:58 ubuntu python: install.run()
Mar 4 18:03:58 ubuntu python: File "/usr/share/ubiquity/plugininstall.py", line 54, in wrapper
Mar 4 18:03:58 ubuntu python: func(self)
Mar 4 18:03:58 ubuntu python: File "/usr/share/ubiquity/plugininstall.py", line 187, in run
Mar 4 18:03:58 ubuntu python: self.remove_extras()
Mar 4 18:03:58 ubuntu python: File "/usr/share/ubiquity/plugininstall.py", line 1214, in remove_extras
Mar 4 18:03:58 ubuntu python: self.do_remove(regular)
Mar 4 18:03:58 ubuntu python: File "/usr/share/ubiquity/plugininstall.py", line 871, in do_remove
Mar 4 18:03:58 ubuntu python: if not cache.commit(fetchprogress, installprogress):
Mar 4 18:03:58 ubuntu python: File "/usr/lib/python2.6/dist-packages/apt/deprecation.py", line 98, in deprecated_function
Mar 4 18:03:58 ubuntu python: return func(*args, **kwds)
Mar 4 18:03:58 ubuntu python: File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 424, in commit
Mar 4 18:03:58 ubuntu python: res = self._fetch_archives(fetcher, pm)
Mar 4 18:03:58 ubuntu python: File "/usr/lib/python2.6/dist-packages/apt/cache.py", line 271, in _fetch_archives
Mar 4 18:03:58 ubuntu python: raise LockFailedException("Failed to lock %s" % lockfile)
Mar 4 18:03:58 ubuntu python: LockFailedException: Failed to lock /target/var/cache/apt/archives/lock
Mar 4 18:03:58 ubuntu python: