[Distutils] patch: solving the two major things that people dislike about setuptools, part 1

[Mark Sienkiewicz]

Ben Finney wrote:
> Mark Sienkiewicz <sienkiew at stsci.edu> writes:
>
>   
>> In that case, the .egg file should go on sys.path immediately before
>> the directory where it is stored. This ensures that a setuptools
>> .egg file will always be discovered before a distutils-installed
>> package/module in the same directory, but it will not override
>> packages/modules that occur earlier in sys.path.
>>     
>
> What of distributions installed via setuptools that are *not*
> installed as eggs?
>
>   

I don't know.  Can you tell me more about that?  I'm not particularly 
familiar with setuptools -- I'm just offering to write the patch because 
I don't see it getting fixed any other way.

Every thing that I have ever installed with setuptools has landed in a 
file or directory named like "*.egg".  For example:
site-packages/nose-0.10.4-py2.5.egg
site-packages/Sphinx-0.5.1-py2.5.egg
site-packages/Jinja-1.2-py2.5-macosx-10.3-i386.egg

The installation creates a file "easy-install.pth" that looks like this:

% cat easy-install.pth
import sys; sys.__plen = len(sys.path)
./setuptools-0.6c9-py2.5.egg
./nose-0.10.4-py2.5.egg
./Sphinx-0.5.1-py2.5.egg
./Jinja-1.2-py2.5-macosx-10.3-i386.egg
./Pygments-1.0-py2.5.egg
./docutils-0.4-py2.5.egg
import sys; new=sys.path[sys.__plen:]; del sys.path[sys.__plen:]; 
p=getattr(sys,'__egginsert',0); sys.path[p:p]=new; sys.__egginsert = 
p+len(new)
%

So, where I said ".egg files", you can substitute the name of the things 
on line 2 through N-1 in the easy-install.pth file. 

That last line of easy-install.pth guarantees that the .egg files (in 
this example, they are all eggs) will be placed in the wrong place on 
sys.path, and that is all I am proposing to fix.  If there is another 
case that does not involve the easy-install.pth file, that is outside 
the scope of my patch.

So, about distributions that are not installed as eggs: Can you tell me 
a little about it?  Can you give me an example of how I can see it 
happen?  Or does it turn out to be irrelevant to my patch?

Mark S.