bzr crashed with AttributeError in /usr/lib/python2.7/dist-packages/bzrlib/plugins/hg/dir.py: 'module' object has no attribute '_LockWarner'

[Barry Warsaw]

$ bzr init-repo uptodate

gave me this crash on oneiric.

$ bzr --version
Bazaar (bzr) 2.4b5
  Python interpreter: /usr/bin/python 2.7.2
  Python standard library: /usr/lib/python2.7
  Platform: Linux-3.0.0-5-generic-x86_64-with-Ubuntu-11.10-oneiric
  bzrlib: /usr/lib/python2.7/dist-packages/bzrlib
  Bazaar configuration: /home/barry/.bazaar
  Bazaar log file: /home/barry/.bzr.log

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: bzr 2.4.0~beta5-2ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-5.6-generic 3.0.0-rc7
Uname: Linux 3.0.0-5-generic x86_64
Architecture: amd64
BzrDebugFlags: set()
BzrVersion: 2.4b5
CommandLine: ['/usr/bin/bzr', 'init-repo', 'uptodate']
CrashDb: bzr
Date: Tue Jul 19 10:50:01 2011
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/bzr
FileSystemEncoding: UTF-8
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110228.1)
InterpreterPath: /usr/bin/python2.7
Locale: en_US.UTF-8
PackageArchitecture: all
Platform: Linux-3.0.0-5-generic-x86_64-with-Ubuntu-11.10-oneiric
ProcCmdline: /usr/bin/python /usr/bin/bzr init-repo uptodate
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, user)
 LANG=en_US.UTF-8
PythonVersion: 2.7.2
SourcePackage: bzr
Title: bzr crashed with AttributeError in /usr/lib/python2.7/dist-packages/bzrlib/plugins/hg/dir.py: 'module' object has no attribute '_LockWarner'
UpgradeStatus: Upgraded to oneiric on 2011-06-17 (31 days ago)
UserEncoding: UTF-8
UserGroups: adm admin cdrom dialout fuse lpadmin plugdev sambashare