[Distutils] shebang line modified by setuptools

[Stephen Waterbury]

Gael Varoquaux wrote:
> 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 you misunderstand my proposal, Gael ...

You and I are using "system Python" to mean different things.
In my proposal, *the* "system Python" and a packaged Python
installed using the system's package manager would be separate
things (and may or may not be the same version of Python)!

What I am proposing:

1)  the OS comes with its own "system Python", which is installed
not as the "python" package, but as some OS-required package
(maybe call it "system-python" or something) and it goes into
/usr/system/bin/python or whatever -- it doesn't matter what the
path is as long as it's not /usr/bin or anything on the default
path.  And system utilities that are python scripts should have
their own system-specific, hard-coded shebang line.

2)  separately from the "system Python", the available packages
shown by the system's package manager include one or more "python.x"
packages which are python interpreters that the user or sysadmin can
optionally install, and which go into /usr.  And the system package
manager -- e.g., apt on Debian/Ubuntu systems) would have all its usual
nicely-packaged python apps (python-this, python-that, ...) that would
also install into /usr and use the nicely-packaged python (not to be
confused with the "system Python" of 1).

Steve