[Distutils] BUG: Python version confusion leads to cryptic errors on Windows

[Mikko Ohtamaa]

When you try to install Python 2.5 built egg on Python 2.4 on Windows, the
install starts fine, but is aborted due to "dependency issue" ("error: Could not
find suitable distribution for Requirement.parse") in the package you are trying
to install. The error message makes the user think there is something wrong in
the package files. However, it would be very friendly to report that the package
you are trying to install is not compatible with Python version.

A sample case below. Trying to install Python 2.5 egg when running Python 2.4.

C:\Documents and Settings\cx\Desktop>"c:\Program Files\Plone 3\Python\Pyth
on.exe" "c:\Program Files\Plone 3\Python\Scripts\easy_install-script.py" ./aura.
theme-1.0.0-py2.5.egg
Processing aura.theme-1.0.0-py2.5.egg
creating c:\program files\plone 3\python\lib\site-packages\aura.theme-1.0.0-py2.
5.egg
Extracting aura.theme-1.0.0-py2.5.egg to c:\program files\plone 3\python\lib\sit
e-packages
  File "c:\program files\plone 3\python\lib\site-packages\aura.theme-1.0.0-py2.5
.egg\aura\theme\skins\aura_theme_custom_templates\createContent.py", line 232
    return run(context)
SyntaxError: 'return' outside function
  File "c:\program files\plone 3\python\lib\site-packages\aura.theme-1.0.0-py2.5
.egg\aura\theme\skins\aura_theme_custom_templates\getSection.py", line 14
    return iter.Title()
SyntaxError: 'return' outside function
  File "c:\program files\plone 3\python\lib\site-packages\aura.theme-1.0.0-py2.5
.egg\aura\theme\skins\aura_theme_styles\plone.css.py", line 26
    return printed
SyntaxError: 'return' outside function
Adding aura.theme 1.0.0 to easy-install.pth file

Installed c:\program files\plone 3\python\lib\site-packages\aura.theme-1.0.0-py2
.5.egg
Processing dependencies for aura.theme==1.0.0
Searching for aura.theme==1.0.0
Reading http://pypi.python.org/simple/aura.theme/
Couldn't find index page for 'aura.theme' (maybe misspelled?)
Scanning index of all packages (this may take a while)
Reading http://pypi.python.org/simple/
No local packages or download links found for aura.theme==1.0.0
error: Could not find suitable distribution for Requirement.parse('aura.theme==1
.0.0')