Can't find importlib when building documentation

[Halo]

I'm attempting to build HTML from the documentation and cannot get it to work. I don't know enough about Python to understand what is wrong and could use some guidance. Does anyone know how I can resolve this issue?

My bzr checkout is up-to-date. I'm using Cygwin on Win7 64-bit. I have Cygwin's Python 2.6.5 package installed. CALIBRE_DEVELOP_FROM is set to /home/owner/calibre/src in bash. I installed Sphinx with the following commands.

wget http://peak.telecommunity.com/dist/ez_setup.py
python ez_setup.py
easy_install -U Sphinx

I then ran the Makefile and got the following errors:

owner@6930-laptop ~/calibre/src/calibre/manual
$ make html
mkdir -p .build/html .build/doctrees
sphinx-build -b html -d .build/doctrees -D latex_paper_size=  . .build/html
Running Sphinx v1.0.7

Exception occurred:
  File "/home/owner/calibre/src/calibre/constants.py", line 15, in <module>
    import sys, locale, codecs, os, importlib, collections
ImportError: No module named importlib
The full traceback has been saved in /tmp/sphinx-err-XYtrkf.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error message can be provided next time.
Either send bugs to the mailing list at <http://groups.google.com/group/sphinx-dev/>,
or report them in the tracker at <http://bitbucket.org/birkenfeld/sphinx/issues/>. Thanks!
make: *** [html] Error 1

/tmp/sphinx-err-XYtrkf.log contains the following.

# Sphinx version: 1.0.7
# Python version: 2.6.5
# Docutils version: 0.7 release
# Jinja2 version: 2.5.5
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/Sphinx-1.0.7-py2.6.egg/sphinx/cmdline.py", line 187, in main
    warningiserror, tags)
  File "/usr/lib/python2.6/site-packages/Sphinx-1.0.7-py2.6.egg/sphinx/application.py", line 104, in __init__
    confoverrides or {}, self.tags)
  File "/usr/lib/python2.6/site-packages/Sphinx-1.0.7-py2.6.egg/sphinx/config.py", line 168, in __init__
    execfile(config['__file__'], config)
  File "/home/owner/calibre/src/calibre/manual/conf.py", line 21, in <module>
    import custom
  File "/home/owner/calibre/src/calibre/manual/custom.py", line 15, in <module>
    from calibre.linux import entry_points
  File "/home/owner/calibre/src/calibre/__init__.py", line 15, in <module>
    from calibre.constants import (iswindows, isosx, islinux, isfrozen,
  File "/home/owner/calibre/src/calibre/constants.py", line 15, in <module>
    import sys, locale, codecs, os, importlib, collections
ImportError: No module named importlib

[kovidgoyal]

importlib exists only in python 2.7 and higher.

[Halo]

Is calibre giving the error or Sphinx? The calibre docs say it works with Python 2.6 while the Sphinx docs say it can work with Python 2.4 or higher.

[kovidgoyal]

calibre needs python >= 2.7