[mod_python] patch to use Py_SetProgramName()

On Wed, Mar 26, 2008 at 03:51:58PM -0500, Graham Dumpleton wrote:
> Even if it fixes things on some platforms, the problem I have with it
> is that it hard codes a path into the executable. If the 'python'
> executable supplied to --with-python was actually a symlink to another
> location, the result will be an incorrect location is used as you
> really want the location pointed at, not where the symlink was.
> Another problem might be where people building binary distributions of
> mod_python use some special Python installation not in the standard
> location. It may work for them when they test it, but when they
> release it it then make break for others because they may not have
> Python installed where person who built it did.

My impression from the description of the Py_SetProgramName() function
was that it provided not so much of a hard-coding to the path but rather
steering the search for the executable to first look at a specific
location before looking in other likely places.

Has that been your experience in using Py_SetProgramName()?

> What was found with mod_wsgi was that it was better to have a
> directive in Apache configuration file which allowed one to set
> PYTHONHOME. 

Apparently, the use of PYTHONHOME would still override the value given
to Py_SetProgramName(), so it doesn't seem to me that you would lose any 
flexibility by its use.

> This still didn't work for Windows, but seemed the best
> compromise. One benefit of making it configurable through the Apache
> configuration file was that that mechanism could then be used to point
> the interpreter at a Python virtual environment isolated from
> site-packages of standard Python installation. For details on this
> see:
> 
>   http://code.google.com/p/modwsgi/wiki/VirtualEnvironments
> 
> You might also read section 'Multiple Python Versions' of:
> 
>   http://code.google.com/p/modwsgi/wiki/InstallationIssues
> 
> which for mod_wsgi talks about the same problem with wrong version of
> Python being found.

One reason for my terseness in my original post was that I couldn't see
any reason (at the time) for not employing Py_SetProgramName(), since it
seemed to me to be the preferred mechanism (if the executable path is
known at compile time) to *correctly* specify the path for a package 
maintainer whose work will end up on other people's systems.  Or to give a 
person like myself (targeting a specialized type of installation) to use 
a symlink that actually points to the desired interpreter, without the
need to define PYTHONHOME (that has complicated things in the past
here).

Anyway, thank you for you attention.

Glen Mabey