py27-sqlalchemy @1.4.1_0 broke buildbot-0.8

[ryandesign (Ryan Carsten Schmidt)]

py27-sqlalchemy @1.4.1_0 broke our buildbot-0.8 setup. I had to go back to py27-sqlalchemy @1.3.23_0 to prevent this from happening on buildmaster startup:

$ sudo -u buildbot env HOME=/opt/local/var/buildmaster TZ=UTC /opt/local/bin/twistd-2.7 --nodaemon --no_save --python=buildbot.tac
:0: UserWarning: You do not have a working installation of the service_identity module: 'No module named service_identity'.  Please install it from <https://pypi.python.org/pypi/service_identity> and make sure all of its dependencies are satisfied.  Without the service_identity module, Twisted can perform only rudimentary TLS client hostname verification.  Many valid certificate/hostname mappings may be rejected.
Unhandled Error
Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/application/app.py", line 674, in run
    runApp(config)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/scripts/twistd.py", line 25, in runApp
    runner.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/application/app.py", line 381, in run
    self.application = self.createOrGetApplication()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/application/app.py", line 453, in createOrGetApplication
    application = getApplication(self.config, passphrase)
--- <exception caught here> ---
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/application/app.py", line 464, in getApplication
    application = service.loadApplication(filename, style, passphrase)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/application/service.py", line 416, in loadApplication
    application = sob.loadValueFromFile(filename, 'application')
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/twisted/persisted/sob.py", line 177, in loadValueFromFile
    eval(codeObj, d, d)
  File "buildbot.tac", line 4, in <module>
    from buildbot.master import BuildMaster
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/buildbot/master.py", line 38, in <module>
    from buildbot.db import connector
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/buildbot/db/connector.py", line 24, in <module>
    from buildbot.db import enginestrategy
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/buildbot/db/enginestrategy.py", line 62, in <module>
    class BuildbotEngineStrategy(strategies.ThreadLocalEngineStrategy):
exceptions.AttributeError: 'module' object has no attribute 'ThreadLocalEngineStrategy'


Failed to load application: 'module' object has no attribute 'ThreadLocalEngineStrategy'

Don't know if this is a bug in py-sqlalchemy or if buildbot-0.8 needs to be changed in some way to accommodate a py-sqlalchemy change.

I'm not very familiar with python but a quick search suggested that unexpected object has no attribute messages might indicate a circular dependency between python files that include each other.