"LookupError: unknown encoding: ascii" when running bootstrap

Question

I'm using zc.buildout, and when I try to run bootstrap (for the first time on a new computer), I'm receiving the following error below:

>> python2.7 bootstrap.py

Traceback (most recent call last):
  File "bootstrap.py", line 158, in <module>
    import pkg_resources
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/../../Extras/lib/python/pkg_resources.py", line 698, in <module>
    class Environment(object):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/../../Extras/lib/python/pkg_resources.py", line 701, in Environment
    def __init__(self, search_path=None, platform=get_supported_platform(), python=PY_MAJOR):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/../../Extras/lib/python/pkg_resources.py", line 99, in get_supported_platform
    plat = 'macosx-%s-%s' % ('.'.join(_macosx_vers()[:2]), m.group(3))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/../../Extras/lib/python/pkg_resources.py", line 209, in _macosx_vers
    _cache.append(mac_ver()[0].split('.'))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/platform.py", line 803, in mac_ver
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/platform.py", line 780, in _mac_ver_xml
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py", line 78, in readPlist
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py", line 406, in parse
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py", line 418, in handleEndElement
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py", line 452, in end_key
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py", line 436, in getData
LookupError: unknown encoding: ascii

Has anyone seen this before or know how to fix it? It appears to have something to do with getting the current version of my operating system. My operating system is Mac 10.8.2.

Thanks!

Answer 1

As Vitaly answered, the problem is indeed that the original .py files are missing in /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/ (there are only .pyc files there in a clean installation). Specifically, these files have to exist for bootstrap.py to succeed:

/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/encodings/__init__.py
/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site.py

You can copy them from a virtualenv or from a different computer.