autopkgtest failure "AssertionError: CanonicalNameDict({'http://xkcd.com/rss.x[101 chars]l')}) != {}"

[Bryce Harrington]

https://autopkgtest.ubuntu.com/results/autopkgtest-impish/impish/amd64/l/limnoria/20210802_195107_55ed2@/log.gz

======================================================================
FAIL: testRemoveAliasedFeed (RSS.test.RSSTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/supybot/test.py", line 214, in runTest
    originalRunTest()
  File "/usr/lib/python3/dist-packages/supybot/plugins/RSS/test.py", line 76, in newf
    f(self, mock)
  File "/usr/lib/python3/dist-packages/supybot/plugins/RSS/test.py", line 112, in testRemoveAliasedFeed
    self.assertEqual(self.irc.getCallback('RSS').feed_names, {})
AssertionError: CanonicalNameDict({'http://xkcd.com/rss.x[101 chars]l')}) != {}

Debian also experiences this same failure:
  - https://ci.debian.net/data/autopkgtest/testing/ppc64el/l/limnoria/14172637/log.gz
  - https://ci.debian.net/data/autopkgtest/testing/ppc64el/l/limnoria/14205329/log.gz

I don't spot obvious bug reports in Debian or Upstream, and there are no upstream commits since 2021.7.21. Previous versions were passing ok both in debian and ubuntu.

Looking at the commits between 2021.06.15, this one caught my eye:
  https://github.com/ProgVal/Limnoria/commit/0af4af16d31998edf721c6bcb1aeff343d188604
  https://github.com/ProgVal/Limnoria/issues/1479

The test in question is:

    @mock_urllib
    def testRemoveAliasedFeed(self, mock):
        mock._data = xkcd_new ### <-- newly added line
        try:
            self.assertNotError('rss announce add http://xkcd.com/rss.xml')
            self.assertNotError('rss add xkcd http://xkcd.com/rss.xml')
        finally:
            self.assertNotError('rss announce remove http://xkcd.com/rss.xml')
            self.assertNotError('rss remove xkcd')
        self.assertEqual(self.irc.getCallback('RSS').feed_names, {})

[Bryce Harrington (bryce)]

I tried reverting the newly added line but the test still failed the same way.

[Launchpad Janitor (janitor)]

This bug was fixed in the package limnoria - 2021.07.21-2

---------------
limnoria (2021.07.21-2) unstable; urgency=medium

  * Add patch from upstream to fix a racy autopkgtest failure. LP: #1938957

 -- Mattia Rizzolo <email address hidden> Sun, 22 Aug 2021 19:17:59 +0200