[Twisted-web] error: "No module named strcred"

[George Wright]

Gidday
I'm Looking for help.
Trying to run twisted and twistd examples (such as from here:
http://www.saltycrane.com/blog/2008/10/running-twisted-perspective-broker-example-twistd/)
I sometimes get a  "No module named strcred" error.
For example:
$ twistd twistd --help

geomacbk:~ georgewr$ twistd --help
Traceback (most recent call last):
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 373, in __str__
     return self.getSynopsis() + '\n' + self.getUsage(width=None)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 407, in getUsage
     for (cmd, short, parser, desc) in self.subCommands:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/application/app.py", line 364, in subCommands
     for plug in plugins:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 227, in getPlugins
     allDropins = getCache(package)
--- <exception caught here> ---
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 178, in getCache
     provider = namedAny(module.__name__ + '.' + moduleName)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/reflect.py", line 357, in namedAny
     topLevelPackage = __import__(trialname)
   File "/Users/georgewr/Library/Python/2.5/site-packages/twisted/ 
plugins/cred_memory.py", line 13, in <module>
     from twisted.cred.strcred import ICheckerFactory
exceptions.ImportError: No module named strcred
Traceback (most recent call last):
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 373, in __str__
     return self.getSynopsis() + '\n' + self.getUsage(width=None)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 407, in getUsage
     for (cmd, short, parser, desc) in self.subCommands:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/application/app.py", line 364, in subCommands
     for plug in plugins:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 227, in getPlugins
     allDropins = getCache(package)
--- <exception caught here> ---
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 178, in getCache
     provider = namedAny(module.__name__ + '.' + moduleName)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/reflect.py", line 357, in namedAny
     topLevelPackage = __import__(trialname)
   File "/Users/georgewr/Library/Python/2.5/site-packages/twisted/ 
plugins/cred_file.py", line 16, in <module>
     from twisted.cred.strcred import ICheckerFactory
exceptions.ImportError: No module named strcred
Traceback (most recent call last):
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 373, in __str__
     return self.getSynopsis() + '\n' + self.getUsage(width=None)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 407, in getUsage
     for (cmd, short, parser, desc) in self.subCommands:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/application/app.py", line 364, in subCommands
     for plug in plugins:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 227, in getPlugins
     allDropins = getCache(package)
--- <exception caught here> ---
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 178, in getCache
     provider = namedAny(module.__name__ + '.' + moduleName)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/reflect.py", line 357, in namedAny
     topLevelPackage = __import__(trialname)
   File "/Users/georgewr/Library/Python/2.5/site-packages/twisted/ 
plugins/cred_unix.py", line 13, in <module>
     from twisted.cred.strcred import ICheckerFactory
exceptions.ImportError: No module named strcred
Traceback (most recent call last):
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 373, in __str__
     return self.getSynopsis() + '\n' + self.getUsage(width=None)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/usage.py", line 407, in getUsage
     for (cmd, short, parser, desc) in self.subCommands:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/application/app.py", line 364, in subCommands
     for plug in plugins:
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 227, in getPlugins
     allDropins = getCache(package)
--- <exception caught here> ---
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/plugin.py", line 178, in getCache
     provider = namedAny(module.__name__ + '.' + moduleName)
   File "/System/Library/Frameworks/Python.framework/Versions/2.5/ 
Extras/lib/python/twisted/python/reflect.py", line 357, in namedAny
     topLevelPackage = __import__(trialname)
   File "/Users/georgewr/Library/Python/2.5/site-packages/twisted/ 
plugins/cred_anonymous.py", line 14, in <module>
     from twisted.cred.strcred import ICheckerFactory
exceptions.ImportError: No module named strcred
Usage: twistd [options]
Options:
       --savestats        save the Stats object rather than the text  
output of
                          the profiler.
   -o, --no_save          do not save state on shutdown
   -e, --encrypted        The specified tap/aos/xml file is encrypted.
       --nothotshot       Don't use the 'hotshot' profiler even if it's
                          available.

........
snip
.........

     manhole          An interactive remote debugger service  
accessible via
                      telnet and ssh and providing syntax coloring and  
basic line
                      editing functionality.
     conch            A Conch SSH service.


George Wright
georgewr at bigpond.net.au
http://mywebsite.bigpond.net.au/georgewr/
http://www.labyrinth.net.au/~gwright