'Unexpected Zope exception' when pushing a branch to Launchpad

[Andrea Corbellini]

Trying to push a branch to Launchpad, but I keep getting this error:

$ bzr push
Using saved push location: lp:beeseek
Traceback (most recent call last):
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/eggs/Twisted-10.1.0-py2.6-linux-x86_64.egg/twisted/internet/defer.py", line 441, in _runCallbacks
    self.result = callback(self.result, *args, **kw)
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/lib/lp/codehosting/vfs/branchfs.py", line 688, in got_path_info
    control_string, branch_string, repository_string)
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/lib/lp/codehosting/vfs/branchfsclient.py", line 122, in branchChanged
    repository_string)
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/lib/lp/services/twistedsupport/xmlrpc.py", line 50, in callRemote
    method_name, *args, **kwargs)
--- <exception caught here> ---
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/eggs/Twisted-10.1.0-py2.6-linux-x86_64.egg/twisted/internet/defer.py", line 125, in maybeDeferred
    result = f(*args, **kw)
  File "/srv/bazaar.launchpad.net/production/launchpad-rev-11738/lib/lp/services/twistedsupport/xmlrpc.py", line 35, in callRemote
    return getattr(self._proxy, method_name)(*args, **kwargs)
  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 "/usr/lib/python2.6/xmlrpclib.py", line 1253, in request
    return self._parse_response(h.getfile(), sock)
  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])
xmlrpclib.Fault: <Fault -1: 'Unexpected Zope exception: AssertionError: '>
Pushed up to revision 112.

A few things to note:
* if you see the last line, the last revision (112) is successfully uploaded, and in fact it shows up on bazaar.lp.net;
* if I re-push, I always get the same traceback (the only difference is the last line: "No new revisions to push");
* on code.lp.net the last revision doesn't show up;
* the commit notification e-mails are not sent.

[Andrea Corbellini (andrea.corbellini)]

I've tried again to push and the traceback no longer appears, code.lp.net is updated and the commit notifications have been sent.
I think this bug can be closed, but if you want to investigate the problem, probably I can provide more information.