[Pythonmac-SIG] Using embedded python programs from DarwinPorts.

[Bob Ippolito]

On Nov 29, 2004, at 4:13 PM, Robert White wrote:

> Excuse me for bringing up the following if it has previously been
> discussed and I missed it.
>
> Recently, I started using DarwinPorts again to install
> some programs that I like to have around.  However, I noticed that
> several programs that embed Python force an installation of python
> 2.3.4 into DarwinPorts for MacOSX 10.3.6 rather than just using the
> built-in python.
>
> So, in the case of Glom, XChat2 and cvs2svn, I started researching
> how to change the appropriate autoconf et al files to properly link to
> or set up in the builtin Python.  (Probably, mostly m4 macros)
> In doing that I contacted two different Port Maintainers asking some
> very basic questions.  One stated that "port" is smart enough to use
> the builtin-Python Framework and not pull in the unix version
> which is not my experience.  The other stated that "The darwinports
> policy for both perl and python modules is to only use the
> darwinports-provided versions of these languages.  The reason is
> that doing something else would require installing files outside of
> the darwinports prefix (which is /opt/local by default).".

port is probably smart enough to bring in Python, but the existing  
autoconf scripts, etc. for the packages probably need to be patched.  A  
lot of them assume -lpython will do the job.  What you *could* do is  
something like the following to trick them:

ln -s /System/Library/Frameworks/Python.framework/Versions/2.3/Python  
/opt/local/lib/libpython2.3.dylib
ln -s /System/Library/Frameworks/Python.framework/Python  
/opt/local/lib/libpython2.dylib
ln -s /System/Library/Frameworks/Python.framework/Python  
/opt/local/lib/libpython.dylib
ln -s  
/System/Library/Frameworks/Python.framework/Versions/2.3/include/ 
python2.3 /opt/local/include/python2.3
ln -s  
/System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3  
/opt/local/lib/python2.3

This is probably enough to trick a naive configure script to find your  
framework python and link to it correctly without changes.. (untested,  
wrote it in mail, didn't want to deactivate my darwinports python to  
try it).

> While I find those comments to be justified, I am wondering if it would
> not be possible to use the builtin version if one were to have their
> own PYTHONPATH environment variable defined and otherwise
> pull in a different version.  (I am probably wrong, but I think that
> a PYTHONPATH variable addresses most of the problem especially
> if it is pointing back into /opt/local somewhere.)

Well you would have to add extra cruft to the "python setup.py install"  
command..  --prefix=/opt/local would be almost sufficient, except that  
if you did the trickery above, the headers and the python packages  
themselves would go to the wrong place.  Unfortunately there isn't  
really a right place if the above trickery is used, because the headers  
would never really be findable by packages that need them (i.e. pygame  
looking for Numeric headers).  This is a general problem with  
distutils.  --install-platlib could put the python packages somewhere  
else just fine though (/opt/local/python/2.3/ maybe).

> I know that this ultimately must be presented to the DarwinPorts
> Group, but I know that several on this list are very active there
> and may indicate to me that this is not a worthwhile investment
> of my time.  So, I wanted to get your opinions first of whether I  
> should
> pursue this or not and if so, any gotchas that you might be aware of.

It's a lot of work, question is do you really want to bother? :)

My only real problem with the darwinports Python is that it uses the  
linker option -undefined suppress -flat_namespace (last I checked)... I  
personally have a whole bunch of Pythons installed for testing  
purposes, so I'm used to the hassle.. though 95% of the time I use the  
stock Python 2.3.0.  At some point I'm going to start contributing port  
and port patches to dp, but I just have high priority things on my  
plate right now.

-bob