When trying to start Buildbot’s master 0.8.6 I encountered this “exceptions.ImportError: cannot import name NoResource” error. The full transcript from the buildbot’s log is shown below:

2012-10-20 21:06:15+0300 [-]  
2012-10-20 21:06:15+0300 [-] Unhandled Error
	Traceback (most recent call last):
	  File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 551, in _runCallbacks
		current.result = callback(current.result, *args, **kw)
	  File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 916, in gotResult
		_deferGenerator(g, deferred)
	  File "/usr/lib64/python2.7/site-packages/twisted/internet/defer.py", line 891, in _deferGenerator
		result = g.next()
	  File "/usr/lib64/python2.7/site-packages/buildbot/master.py", line 166, in startService
		self.configFileName)
	---  ---
	  File "/usr/lib64/python2.7/site-packages/buildbot/config.py", line 144, in loadConfig
		exec f in localDict
	  File "/home/buildbot/master/master.cfg", line 307, in 
		from buildbot.status.html import WebStatus
	  File "/usr/lib64/python2.7/site-packages/buildbot/status/html.py", line 20, in 
		from buildbot.status.web.baseweb import WebStatus
	  File "/usr/lib64/python2.7/site-packages/buildbot/status/web/baseweb.py", line 35, in 
		from buildbot.status.web.changes import ChangesResource
	  File "/usr/lib64/python2.7/site-packages/buildbot/status/web/changes.py", line 19, in 
		from twisted.web.error import NoResource
	

2012-10-20 21:06:15+0300 [-] Configuration Errors:
2012-10-20 21:06:15+0300 [-]   error while parsing config file: cannot import name NoResource (traceback in logfile)
2012-10-20 21:06:15+0300 [-] Halting master.
2012-10-20 21:06:15+0300 [-] Main loop terminated.
2012-10-20 21:06:15+0300 [-] Server Shut Down.

This has been fixed in 0.8.7, but if you can’t upgrade to 0.8.7 for whatever reason, see https://github.com/buildbot/buildbot/pull/509 for the explanation and patch. First locate where your python site-packages are (mine as shown below is in /usr/lib64/python2.7/site-packages. You figure this out by executing:

# python -m site

sys.path = [
    '/home/buildbot/master',
    '/usr/lib64/python27.zip',
    '/usr/lib64/python2.7',
    '/usr/lib64/python2.7/plat-linux2',
    '/usr/lib64/python2.7/lib-tk',
    '/usr/lib64/python2.7/lib-old',
    '/usr/lib64/python2.7/lib-dynload',
    '/usr/lib64/python2.7/site-packages',
    '/usr/lib64/python2.7/site-packages/gtk-2.0',
    '/usr/lib64/portage/pym',
]
USER_BASE: '/root/.local' (exists)
USER_SITE: '/root/.local/lib64/python2.7/site-packages' (doesn't exist)
ENABLE_USER_SITE: True

Then, all you have to do is replace:

from twisted.web.error import NoResource

with

try:
    from twisted.web.error import NoResource
except ImportError:
    from twisted.web.error import Error as NoResource

in 3 files:

/usr/lib64/python2.7/site-packages/buildbot/status/web/changes.py
/usr/lib64/python2.7/site-packages/buildbot/status/web/logs.py
/usr/lib64/python2.7/site-packages/buildbot/status/web/slaves.py