[Distutils] shebang line modified by setuptools

[Gael Varoquaux]

On Sun, Apr 13, 2008 at 11:16:57AM -0400, Stephen Waterbury wrote:
> > On Debian and derivatives (e.g. Ubuntu) you might have even more fun.  
> > They put /usr/local/lib/pythonX.Y/site-packages on the sys.path *of the 
> > system python*!  This means that you can break your system Python by 
> > installing a version of Python from source and then distutil'ing things 
> > into there.  Astoundingly, this is promoted as a feature.

> That *is* astounding.  I've been using Ubuntu for several years now,
> and I blush to admit I never noticed that until just the other day when
> I tried installing Python 2.6 from source (into the default /usr/local
> location, of course) and it broke all my running web stuff, so I hastily
> removed it -- sheesh!

> As I mentioned, I've been "lazy" about using the system Python for my
> own apps and development, but I would feel much more comfortable if
> the system Python had its own space.

> > I've reported bugs on this and had discussions with some of the Debian 
> > Python packaging folks.  I'm hoping that we'll find a solution that 
> > doesn't collide with a from-source default Python build.

Well, I am not too happy about what I hear here. It seems to me as if
Ubuntu is headed the macOS X way, where (it seems) that a second Python
needs to be installed on top of the system Python to add modules to it. I
know it is not exactly the case, but this change is _really_ going to
confuse people and I can this the mailing lists of module developper
pilling up with requests for help. There needs to be a way for the user
to install his own modules and keep using the system Python. I think it
is a very bad idea to do it in /usr. Yes, you can teach your users to add
things to their PYTHONPATH, but this put one additional thing to learn
for people who just want to get things done. I think users are going to
hate this.

Maybe something less drastic can be done, by making sure that the
/usr/local is far in the PYTHONPATH, that way packages installed in
/usr/local do not override the system packages. Of course setuptools will
break this, because it adds itsef to front of the PYTHONPATH, and totally
break the PYTHONPATH semantics (Grrr). 

I still think you guys have it wrong, and if you want a new Python
install, you do it in /opt. For me /usr/local is for user programs that
cooperate for system programs.

My 2 cents,

Gaël