some updates can't be checked from the main list

The actual fix works fine (I can run it from the source directory), but something is weird: If I build the branch and install the debs, and start u-m I get:

$ update-manager
Traceback (most recent call last):
  File "/usr/bin/update-manager", line 37, in <module>
    from UpdateManager.UpdateManager import UpdateManager
ImportError: No module named UpdateManager.UpdateManager

This seems to have nothing to do with that particular change, much rather a recent change in our py3 build chain. binary debdiff doesn't show any difference, and /usr/lib/python3/dist-packages/UpdateManager/UpdateManager.py exists.

Can you reproduce this?

Yes. Something is causing the shebang line to be /usr/bin/python instead of python3... Looking into it.

See https://code.launchpad.net/~mterry/update-manager/dh9/+merge/149882

This bug was fixed in the package update-manager - 1:0.183

---------------
update-manager (1:0.183) raring; urgency=low

  [ Mike Terry ]
  * Fix toggling items after doing a deselect-all. (LP: #1129191)

  [ Colin Watson ]
  * Fix PEP-8 failures.
  * Fix pyflakes failures.
  * Depend on pep8 and pyflakes for the autopkgtest suite.
  * Use logging.warning rather than deprecated logging.warn.
  * Fix test_meta_release_core.SillyProxyRequestHandler to write bytes
    rather than text to its output file object.
  * Make test_meta_release_core pick a new proxy port for each test.
  * Use EnvironmentVarGuard in test_meta_release_core to reduce the risk of
    test isolation bugs.
  * MetaReleaseCore: Plug some open file object leaks.
  * Make test_meta_release_core call install_opener(None) every time it
    changes proxy settings, to avoid stale ones being left around from
    previous tests.
  * Reopen cache in GroupingTestCase.setUp, TestCache.setUp, and
    TestChangelogs.setUp to avoid test isolation bugs.
  * Remove unnecessary cache update in PhasedTestCase.setUp; reopening the
    cache is sufficient.
  * Allow saveDistUpgrade to remove packages provided that upgrade
    candidates declare Conflicts+Replaces+Provides on them (LP: #1038113).

  [ Steve Langasek ]
  * Build-depend on python3-all (>= 3.3.0-2) for pybuild support and drop
    the now-extraneous overrides from debian/rules; this incidentally works
    around an issue I don't understand where the package was now failing to
    build locally from trying to invoke python setup.py instead of python3.
 -- Colin Watson <email address hidden> Mon, 25 Feb 2013 17:31:29 +0000