Failing test in provisioningserver.tests.test_config

[Dougal Matthews]

This test fails in CI or locally.

provisioningserver.tests.test_config.TestClusterConfiguration.test_default_tftp_root

09:15:20 ======================================================================
09:15:20 FAIL: provisioningserver.tests.test_config.TestClusterConfiguration.test_default_tftp_root
09:15:20 ----------------------------------------------------------------------
09:15:20 Traceback (most recent call last):
09:15:20 testtools.testresult.real._StringException: Empty attachments:
09:15:20 Twisted logs
09:15:20
09:15:20 Traceback (most recent call last):
09:15:20 File "/run/build/maas/src/maastesting/runtest.py", line 126, in _run_user
09:15:20 result = function(*args, **kwargs)
09:15:20 File "/run/build/maas/.ve/lib/python3.6/site-packages/testtools/testcase.py", line 719, in _run_test_method
09:15:20 return self._get_test_method()()
09:15:20 File "/run/build/maas/src/provisioningserver/tests/test_config.py", line 657, in test_default_tftp_root
09:15:20 "/var/lib/maas/boot-resources/current", config.tftp_root
09:15:20 File "/run/build/maas/.ve/lib/python3.6/site-packages/testtools/testcase.py", line 411, in assertEqual
09:15:20 self.assertThat(observed, matcher, message)
09:15:20 File "/run/build/maas/.ve/lib/python3.6/site-packages/testtools/testcase.py", line 498, in assertThat
09:15:20 raise mismatch_error
09:15:20 testtools.matchers._impl.MismatchError: !=:
09:15:20 reference = '/var/lib/maas/boot-resources/current'
09:15:20 actual = '/run/build/maas/.run/maas/boot-resources/current'