The Google App Engine SDK is broken on Ubuntu 10.10, but it's easy enough to fix...
The Google App Engine SDK requires Python 2.5. It does not work with Python 2.6.
This problem is covered in these Google Code issues:
http://code.google.com/p/googleappengine/issues/detail?id=1159
http://code.google.com/p/googleappengine/issues/detail?id=757
If you try to use Google App Engine SDK on Python 2.6 you will encounter tracebacks like the following:
Traceback (most recent call last):
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 3211, in _HandleRequest
self._Dispatch(dispatcher, self.rfile, outfile, env_dict)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 3154, in _Dispatch
base_env_dict=env_dict)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 527, in Dispatch
base_env_dict=base_env_dict)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 2452, in Dispatch
CGIDispatcher.Dispatch(self, *args, **kwargs)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 2404, in Dispatch
self._module_dict)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 2441, in curried_exec_cgi
return ExecuteCGI(*args, **kwargs)
File "/home/david/lib/google_appengine/google/appengine/tools/dev_appserver.py", line 2312, in ExecuteCGI
logging.debug('Executing CGI with env: %s', pprint.pformat(env))
File "/usr/lib/python2.6/pprint.py", line 60, in pformat
return PrettyPrinter(indent=indent, width=width, depth=depth).pformat(object)
File "/usr/lib/python2.6/pprint.py", line 119, in pformat
self._format(object, sio, 0, 0, {}, 0)
File "/usr/lib/python2.6/pprint.py", line 137, in _format
rep = self._repr(object, context, level - 1)
File "/usr/lib/python2.6/pprint.py", line 230, in _repr
self._depth, level)
File "/usr/lib/python2.6/pprint.py", line 242, in format
return _safe_repr(object, context, maxlevels, level)
File "/usr/lib/python2.6/pprint.py", line 284, in _safe_repr
for k, v in _sorted(object.items()):
File "/usr/lib/python2.6/pprint.py", line 75, in _sorted
with warnings.catch_warnings():
File "/usr/lib/python2.6/warnings.py", line 333, in __init__
self._module = sys.modules['warnings'] if module is None else module
KeyError: 'warnings'
... which is a pain in the proverbial to debug.
Ubuntu Maverick 10.10 (and some earlier releases of Ubuntu) uses Python 2.6 by default. In older versions of Ubuntu the fix involved installing the older Python 2.5 from the official repository. However, with Ubuntu Maverick 10.10 things are worse... Python 2.5 is no longer available from an official repository!
Thankfully, there is a repository on Launchpad that contains the necessary packages. To install, do the following:
sudo add-apt-repository ppa:fkrull/deadsnakes
sudo apt-get update
sudo apt-get install python2.5
Next, modify dev_appserver.py in the Google App Engine SDK. Change the first line from:
#!/usr/bin/env python
to:
#!/usr/bin/env python2.5
Simple. Done. Restart your dev_appserver.py and everything should work A-OK.
