Moving to newer Python versions

With Lucid fast approaching, efforts to actually migrate Launchpad to Python 2.6 are getting under way.

Relevant tagged bugs: https://bugs.launchpad.net/launchpad-foundations/+bugs?field.tag=python-upgrade

Branches

• https://code.launchpad.net/~launchpad-committers/launchpad/python2.6 -- collaboration branch created by maxb based on salgado's personal branch

• https://code.launchpad.net/~salgado/shipit/shipit-python2.6

Issues that need revisiting

• The failure when setting up the GoogleServiceLayer seems to be a consequence of the server answering with a errno.ECONNABORTED when it's not yet ready, so salgado has just changed the wait_for_service function to treat that error the same way it does for errno.ECONNREFUSED.

• The test hang is because of the change done on bug 349316, so salgado has just commented out that addCleanup() line for now, to see if we can get a full test run.

• A multitude of modules of modules (sha, md5, sets, ...) are deprecated in Python 2.6, and many tests would fail merely because of unexpected DeprecationWarnings, so we've had to jump through multiple hoops all over the place to suppress these. Ultimately we need a plan for removing these suppressions, because we want to know about deprecation long-term.

Setup caveats

• The extension modules in your sourcecode directory will have been built for Python 2.5 and these will break for your 2.6 branch. The simple thing to do is to move your old sourcecode aside and run utilities/rocketfuel-get to get it again with Python 2.6. A more complex but useful thing to do to manage sourcecode directories for multiple python versions is:

  cd ~/launchpad/lp-sourcedeps
  mkdir 2.6
  cd 2.6
  ln -s ../download-cache
  ln -s ../eggs
  mkdir sourcecode
  cd sourcecode
  for i in ../../sourcecode/*; do bzr checkout --lightweight "$i"; done

  and now point utilities/link-external-sourcecode to ../../lp-sourcedeps/2.6 - if you do that you'll need to be aware that rocketfuel-get won't know about it, and your extra directories will require occasional manual updating.

Cleanup potential

• Is there any reason we need ipython-0.9.1-py2.5.egg in egg, not tarball, form?
  • Presumably we could bin the wadllib 0.1 eggs too.

• Eventually we should get rid of all the scripts hardcoded /usr/bin/pythonX.Y and use buildout's shebang munging.

• scripts/branch-rewrite.py uses /usr/bin/pythonX.Y -u. We should figure out if this is significant and why this script has to be different from other scripts.

• scripts/ftpmaster-tools/_syncorigins.py uses /usr/bin/env pythonX.Y... why?!

• cronscripts/mirror-prober.sh and cronscripts/nightly.sh are invoking python scripts with explicit interpreters. Why are they not using the shebangs? This leads to versions being defined in two places.

Known test failures and notes thereon

These results assume you:

• Use the lp:~launchpad-committers/launchpad/python2.6 branch

• Have a locally patched sourcecode/pygpgme:

  --- src/pygpgme-context.c       2008-10-16 07:44:55 +0000
  +++ src/pygpgme-context.c       2010-02-19 01:48:46 +0000
  @@ -92,6 +92,8 @@
           return -1;
       }
   
  +    gpgme_check_version(NULL);
  +
       if (pygpgme_check_error(gpgme_new(&self->ctx)))
           return -1;
   

• Do not have python-tdb installed, which otherwise causes bzr-hg and bzr-git to behave in ways the tests do not expect.

• Have the following not-yet-landed branches merged:
  • lp:~maxb/launchpad/trivial-bad-httpcaller-constructor-invocation
  • lp:~maxb/launchpad/py2.6-warnings-monkeypatching
  • lp:~maxb/launchpad/tolerate-lucid-apt-ftparchive
  • lp:~wgrant/launchpad/emailauthentication.txt-2.6-fix
  • lp:~wgrant/launchpad/do-not-shallow-copy-os.environ

BaseLayer: OK (281 tests)

MemcachedLayer: OK (8 tests)

LibrarianLayer: OK (9 tests)

DatabaseLayer: OK (46 tests)

LaunchpadLayer: OK (24 tests)

ZopelessLayer: OK (20 tests)

MailmanLayer: ??

• Note: These do not run automatically. Use bin/test --layer=MailmanLayer

• You may get failures when you run all the tests in one go. Try running each individually for more accurate results.

LaunchpadScriptLayer: OK (85 tests)

n=== LaunchpadZopelessLayer ===

• test_bug_496988 (lp.bugs.scripts.tests.test_checkwatches.TestCheckwatchesWithSyncableGnomeProducts)

  Traceback (most recent call last):
  _StringException: Text attachment: traceback
  ------------
  Traceback (most recent call last):
    File "/home/maxb/launchpad/lp-sourcedeps/eggs/testtools-0.9.2-py2.6.egg/testtools/runtest.py", line 128, in _run_user
      return fn(*args)
    File "/home/maxb/launchpad/lp-sourcedeps/eggs/testtools-0.9.2-py2.6.egg/testtools/testcase.py", line 368, in _run_test_method
      testMethod()
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/scripts/tests/test_checkwatches.py", line 109, in test_bug_496988
      gnome_bugzilla, [bug_watch_1, bug_watch_2])
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/scripts/checkwatches/updater.py", line 522, in _getExternalBugTrackersAndWatches
      remote_bug_ids))
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/externalbugtracker/bugzilla.py", line 617, in getProductsForRemoteBugs
      self.initializeRemoteBugDB(bug_ids)
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/externalbugtracker/isolation.py", line 64, in wrapper
      return func(*args, **kwargs)
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/externalbugtracker/bugzilla.py", line 568, in initializeRemoteBugDB
      'permissive': True,
    File "/usr/lib/python2.6/xmlrpclib.py", line 1199, in __call__
      return self.__send(self.__name, args)
    File "/usr/lib/python2.6/xmlrpclib.py", line 1489, in __request
      verbose=self.__verbose
    File "/home/maxb/launchpad/lp-branches/real-python-2.6/lib/lp/bugs/externalbugtracker/xmlrpc.py", line 98, in request
      response = self._parse_response(self.opener.open(request), None)
    File "/usr/lib/python2.6/xmlrpclib.py", line 1392, in _parse_response
      return u.close()
    File "/usr/lib/python2.6/xmlrpclib.py", line 838, in close
      raise Fault(**self._stack[0])
  Fault: <Fault Client: "Content-Type must be 'text/xml,' 'multipart/*,' or 'application/dime' instead of 'application/x-www-form-urlencoded'">
  ------------

• lib/canonical/launchpad/ftests/../../../lp/bugs/tests/bugs-emailinterface.txt -- tests for http://bugs.python.org/issue7082, which has been fixed.

  • wgrant has a fix, but needs to check with Bugs. Will have to land in the 2.6 branch.

FunctionalLayer: OK (174 tests)

LaunchpadFunctionalLayer

• valid_absolute_url (canonical.launchpad.validators.url) -- Python 2.6's urlparse disregards the uses_netloc list when parsing urls and treats anything beginning with // as netloc based. This makes maxb and wgrant say WTF!?! The untested valid_absolute_url DB constraint is also affected!

AppServerLayer: OK (143 tests)

DatabaseFunctionalLayer: OK (4467 tests)

GoogleLaunchpadFunctionalLayer: OK (72 tests)

PageTestLayer: OK (6335 tests)

TwistedLayer: OK (235 tests)

TwistedLaunchpadZopelessLayer: OK (16 tests)

TwistedAppServerLayer: OK (9 tests)

ZopelessAppServerLayer

• test_hosted_branch_stacked_on_mirrored_branch (lp.codehosting.puller.tests.test_acceptance.TestBranchPuller): LayerIsolationError: Test left new live threads: [<Thread(Thread-3, started daemon 47618947405584)>]

  • This is because of the join() that salgado commented out in this branch, since it hangs. mwhudson has some ideas on resolving the hang.

ZopelessDatabaseLayer: OK (259 tests)

BugsWindmillLayer: OK (13 tests)

CodeWindmillLayer: OK (12 tests)

ForeignBranchPluginLayer: OK (61 tests)

SSHServerLayer: OK (46 tests)

RegistryWindmillLayer: OK (17 tests)

SoyuzWindmillLayer: OK (2 tests)

TestZopeTestInSubProcessLayer: OK (1 test)

TranslationsWindmillLayer: OK (7 tests)

UnitTests: OK

Shipit

Might be ok now, I've fixed the errors that were listed here, but I don't have access to shipit --maxb.