Improve diagnostics in self-test

[Daniel Macks]

p-d-e-2.38 test/auto.py failed a test for me:

======================================================================
FAIL: test_requires_provides (__main__.T)
automatic requires/provides
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test/auto.py", line 678, in test_requires_provides
    self.fail('You need to have pkg_resources, httplib2, and gi.repository.GLib installed for this test suite to work')
AssertionError: You need to have pkg_resources, httplib2, and gi.repository.GLib installed for this test suite to work

----------------------------------------------------------------------

There's no info about which part of the multiprong requirement failed. Instead of a single "try" for multiple imports, a loop over them would make it easy to emit the specific package that failed. Wit the attached patch, I get:

======================================================================
FAIL: test_requires_provides (__main__.T)
automatic requires/provides
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test/auto.py", line 677, in test_requires_provides
    self.fail('You need to have %s installed for this test suite to work' % needed_pkg)
AssertionError: You need to have gi.repository.GLib installed for this test suite to work

----------------------------------------------------------------------

So now I know exactly which dep is missing (or if I think I have it, which is broken).

[Martin Pitt (pitti)]

Applied, thank you!

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "loop-try-import.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Launchpad Janitor (janitor)]

This bug was fixed in the package python-distutils-extra - 2.39-1

---------------
python-distutils-extra (2.39-1) unstable; urgency=medium

  * test/auto.py: Show exactly which modules are missing. Thanks Daniel Macks!
    (LP: #1303550)
  * Ignore comment in second line when parsing *.ui files. Thanks marmuta!
    (LP: #1393247)
  * Drop obsolete X-Python-Version.
  * Convert build systemd to pybuild.
  * Bump Standards-Version to 3.9.6.
  * debian/copyright: Rename field to "Format:".

 -- Martin Pitt <email address hidden> Wed, 03 Feb 2016 09:56:55 +0100