[Distutils] easy_install and sys.path

[Matt Good]

You seem to have missed the main point of Tres's email.  The problem is 
not inherent to Eggs, but you seem to have either set PYTHONPATH or have 
a .pth file that's being loaded which is telling your /usr Python to 
look in the /usr/local Python's site-packages folder.  Packages 
installed to /usr/local in the traditional way would still be on 
sys.path and would have the exact same problem.  So check your 
PYTHONPATH and grep your .pth files in /usr/lib/python2.5/site-packages 
for any references to /usr/local and remove them.

-- Matt Good

Bryan Lawrence wrote:
> Hi Tres
>
> Oh I know I shouldn't mix two pythons, but I've never had them "mixed" before.
> (We have run our own python in /usr/local for yonks without any bad karma 
> until now).  It's only the advent of eggs, which push things to the top of 
> sys.path that causes a problem. It would appear that I'm not the only person 
> who has the problem (e.g. see 
> http://www.rexx.com/~dkuhlman/python_comments.html).
>
> So, my question to this list is "why"?
>
> Why does easy_install put things in the front of sys.path? Presumably there is 
> some good reason (perhaps it is the only way to ensure that your dependency
> libraries are the ones that are picked up, I guess there is a risk that older
> libraries might exist ... but it causes problems for the reasons that Dave 
> Kuhlman lists in his page linked above ).
>
> It would appear that there is fairly long established python behaviour 
> that "new" libraries go after "old" libraries, which easy_install has broken. 
> At this stage, all I want to do is understand why easy_install chose to do 
> that.
>
> I've been a big fan of eggs, but I've just slammed into a wall. I can't 
> believe that I'm the only one for whom this may be a problem.  I now need to 
> work out what, if anything, I need to do about it (change my behaviour, find 
> out something I didn't know about egg installation, provide a suggested 
> optional change to egg behaviour, go home have a drink etc ...)
>
> Cheers
> Bryan
>
> On Tuesday 08 May 2007 17:20:45 Tres Seaver wrote:
>   
>> Bryan Lawrence wrote:
>>     
>>> Can anyone point me to why easy_install forces modules to the front
>>> of sys.path? It seems to break long established rules about ordering
>>> of path variables,  and certainly breaks python in some unexpected
>>> contexts e.g:
>>> https://bugs.launchpad.net/ubuntu/+source/kubuntu-meta/+bug/113298
>>>       
>> In your case, you have libraries mixed from two different version s of
>>
>> python.  From that launchpad issue:
>>     
>>> ok, and quite clearly my path has all the /usr/local stuff in it first:
>>>       
>>>>>> import sys
>>>>>> print sys.path
>>>>>>             
>>> ['',
>>>       
>> '/usr/local/lib/python2.5/site-packages/simplejson-1.4-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/Amara-1.1.9-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/flup-0.5-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/scgi-1.12-py2.5-linux-i686.egg',
>> '/usr/local/lib/python2.5/site-packages/Paste-1.0-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/ZSI-2.0.dev_r1293-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/dap-2.2.5.1-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/httplib2-0.2.0-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/Cheetah-2.0rc7-py2.5-linux-i686.egg
>> ',
>> '/usr/local/lib/python2.5/site-packages/dap.plugins.grads-0.1.1-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/arrayterator-0.2.5-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/PasteDeploy-1.0-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/PasteScript-1.0-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/dap.plugins.netcdf-0.3.2-py2.5.egg'
>> , '/usr/local/lib/python2.5/site-packages/pupynere-0.2.1-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/wsgistate-0.4-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/SQLAlchemy-0.3.3-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/WSGIUtils-0.7-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/setuptools-0.6c5-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/kid-0.9.5-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/PyOpenGL-3.0.0a5-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/Genshi-0.4-py2.5.egg',
>> '/usr/local/lib/python2.5/site-packages/wsgilog-0.1-py2.5.egg',
>> '/usr/lib/python25.zip', '/usr/lib/python2.5',
>> '/usr/lib/python2.5/plat-linux2', '/usr/lib/python2.5/lib-tk',
>> '/usr/lib/python2.5/lib-dynload',
>> '/usr/local/lib/python2.5/site-packages',
>> '/usr/lib/python2.5/site-packages', '/var/lib/python-support/python2.5']
>>
>> AFAIK, This can only happen because you have a .pth file in some 'site'
>> directory which is mistakenly pulling in the "alien" eggs, which should
>> never happen.  *None* of those eggs are guaranteed to work in a
>> different Python than the one which built them;  in your case, the UCS2
>> vs. UCS4 bit is interfering, but it could equally well be a different
>> dynload problem.
>>
>> If you run with 'site' stuff disabled, is your sys path free of those
>> eggs?  E.g.:
>>
>>  $ /usr/bin/python -S
>>
>> If so, find the errant .pth file and remove it (or fix the paths in it).
>>
>>
>> Tres.
>>     
>
>
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