fake librarian columns cannot be looked up by storm

I wanted to use the fake librarian in a test, but ran into a problem. The backtrace:

Error in test lp.code.model.tests.test_branch.TestBranch.test_link_stream
Traceback (most recent call last):
_StringException: Text attachment: traceback
------------
Traceback (most recent call last):
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/testtools-0.9.8-py2.6.egg/testtools/runtest.py", line 169, in _run_user
    return fn(*args, **kwargs)
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/testtools-0.9.8-py2.6.egg/testtools/testcase.py", line 499, in _run_test_method
    return self._get_test_method()()
  File "/home/robertc/launchpad/lp-branches/working/lib/lp/code/model/tests/test_branch.py", line 391, in test_link_stream
    blob = self.factory.makeBlob(' ')
  File "/home/robertc/launchpad/lp-branches/working/lib/lp/testing/factory.py", line 335, in with_default_master_store
    return func(*args, **kw)
  File "/home/robertc/launchpad/lp-branches/working/lib/lp/testing/factory.py", line 3498, in makeBlob
    new_uuid = getUtility(ITemporaryStorageManager).new(blob, expires)
  File "/home/robertc/launchpad/lp-branches/working/lib/canonical/launchpad/database/temporaryblobstorage.py", line 139, in new
    TemporaryBlobStorage(uuid=new_uuid, file_alias=file_alias)
  File "/home/robertc/launchpad/lp-branches/working/lib/canonical/database/sqlbase.py", line 215, in __init__
    self._create(None, **kwargs)
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/storm-0.18-py2.6-linux-x86_64.egg/storm/sqlobject.py", line 294, in _create
    self.set(**kwargs)
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/storm-0.18-py2.6-linux-x86_64.egg/storm/sqlobject.py", line 300, in set
    setattr(self, attr, value)
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/storm-0.18-py2.6-linux-x86_64.egg/storm/references.py", line 194, in __set__
    self._relation.link(local, remote, True)
  File "/home/robertc/launchpad/lp-sourcedeps/eggs/storm-0.18-py2.6-linux-x86_64.egg/storm/references.py", line 651, in link
    remote_var = remote_vars[remote_column]
KeyError: <storm.properties.PropertyColumn object at 0x5f421d0>
------------

remote_column has a table of LibraryFileAlias and a name of id. However remove_vars only has columns for *InstrumentedLibraryFileAlias*, so the lookup fails.

This is enough to reproduce:

class TestBranch(TestCaseWithFactory):
    """Test basic properties about Launchpad database branches."""

    layer = DatabaseFunctionalLayer

    def test_link_stream(self):
        # Linking a stream creates a SubunitStream.
        branch = self.factory.makeBranch()
        self.useFixture(FakeLibrarian())
        # ' ' is a small legitimate subunit stream.
        blob = self.factory.makeBlob(' ')

I'm marking this high because faster tests are generally important.