persistent paramiko DeprecationWarning: integer argument expected, got float on hardy

[Vincent Ladeuil]

For a couple of weeks, bzrlib.tests.blackbox.test_upgrade.SFTPTests.test_upgrade_url is failing on hardy:
Traceback (most recent call last):
  File "/home/babune/lib/python/testtools/runtest.py", line 144, in _run_user
    return fn(*args)
  File "/home/babune/lib/python/testtools/testcase.py", line 465, in _run_test_method
    testMethod()
  File "/home/babune/babune/slaves/hardy32.local/workspace/selftest-hardy/bzrlib/tests/blackbox/test_upgrade.py", line 213, in test_upgrade_url
    self.assertEqual('', err)
AssertionError: not equal:
a = ''
b = "/home/babune/lib/python/paramiko/message.py:226: DeprecationWarning: integer argument expected, got float\n self.packet.write(struct.pack('>I', n))\n"

[Vincent Ladeuil (vila)]

This is rather puzzling as './bzr selftest -s bzrlib.tests.blackbox.test_upgrade.SFTPTests.test_upgrade_url' succeeds.

But './bzr selftest -s bzrlib.tests.blackbox --parallel=fork' fails !

[Vincent Ladeuil (vila)]

Even more surprising: we already have:

# Disable one particular warning that comes from paramiko in Python2.5; if
# this is emitted at the wrong time it tends to cause spurious test failures
# or at least noise in the test case::
#
# [1770/7639 in 86s, 1 known failures, 50 skipped, 2 missing features]
# test_permissions.TestSftpPermissions.test_new_files
# /var/lib/python-support/python2.5/paramiko/message.py:226: DeprecationWarning: integer argument expected, got float
# self.packet.write(struct.pack('>I', n))
warnings.filterwarnings('ignore',
        'integer argument expected, got float',
        category=DeprecationWarning,
        module='paramiko.message')

in bzrlib.transport/sftp/py...

[Vincent Ladeuil (vila)]

I strongly suspect an isolation problem here that is triggered by spiv's change related to the tests partitioning for parallel=fork.

As for the warning itself, it has been fixed in more recent versions of paramiko (hardy uses 1.6.4-1.1)
based on a proposal by... our own poolie ;)

[Vincent Ladeuil (vila)]

Bingo, via trial and error I found one combination that triggers the problem,
running the following tests with --load-list is enough to reproduce:
 bzrlib.tests.blackbox.test_selftest.TestOptions.test_subunit
 bzrlib.tests.blackbox.test_upgrade.SFTPTests.test_upgrade_url

[Vincent Ladeuil (vila)]

So, the root cause is that cmd_selftest calls activate_deprecation_warnings() and blackbox/test_selftest
redefine tests.selftest to test the arguments received.