Re: python-central comments

[abo@minkirri.apana.org.au (Donovan Baarda)]

On Sat, Aug 24, 2002 at 07:48:31PM +0200, Matthias Klose wrote:
> Some comments:
> 
> - python-central should have a configuration option, how files are
>   compiled. Most users don't need compilation with -O. Maybe
>   a debconf option?

Hmm, could be done I guess, but this is already more than the current
standard offers... can't we add this in _after_ python-central becomes a
standard?

> - A separate command to install a python version would be useful.
>   Assume I rename the packages again, or you want it to use for
>   jython as well.

As the person who originally "simplified out" the seperate command for
installing python versions, I can see your point.

Currently the register-python-package does have seperate code for installing
python and modules internally. I originaly thought that the extra flexibility
the seperate commands gave was unnecisary. 

Now I'm not sure, but I'm also not sure that it is simple to have something
generic enough to support jython etc. I have a feeling any sort of attempt
at a generic solution will need to be "fixed beyond compatability" when it
gets tested in the wild anyway.

Unless someone can come up with some hard examples and possible solutions
I'd be wary of trying to see the future in this case.

> - A package should have the possibility that it's incompatibe with
>   a specific python version or that it only works with specific
>   versions.

This is already supported. Packages that support more than one version of
python specify it in their dependancies;

Depends: python1.5 | python1.6 | python2.1, python-central

> - A command is missing to recompile all registered packages when
>   the default python version changes.

This is not needed. The default python just installs a pythonX.Y package.
Provided the default pythonX.Y is already installed, then the registered
packages are already "registered" for it. If then new default pythonX.Y is
not already installed, then all the packages will be "registered" for it
when it gets installed as a dependancy of the new "python" package.

Note that I use "registered" in quotes. python-central no longer really
registers packages, instead it uses the dpkg dependancies to identify what
packages depend/support on what versions of python.

> - How do packages like mailman make profit from python-central?
>   They don't install into /usr/lib/python/site-packages, but
>   their python files need to be recompiled on a python version
>   change.

This is tricky. The current register-python-package says this;

       will  do  the  correct inverse.  Note that if your package
       does    not    install    its     .py     modules     into
       /usr/lib/python/site-packages,  the modules wont be regis­
       tered! See the notes on how to do this.
       :
       :
NOTES
       Python  modules should be distributed with the Python Dis­
       tutils.  Debian scripts can call this line to install  .py
       files into the build-tree:
         python  setup.py  install --root=$(CURDIR)/debian/<pack­age> \
         --install-purelib=/usr/lib/python/site-packages    --no-compile

The problem is that python-central requires *.py dirs to be symlinked from a
different directory for each python version installed. For this to work,
Mailman would need to install it's *.py files into a directory not on any
python-path, and python-central would need to create symlinks to them for
each supported python version in a different directory, where that directory
_is_ on the python-path for the appropriate python version.

I'm not sure of the upstream Mailman structure, but I suspect this would
require major work on the part of the packager to re-structure it to support
this, even if python-central did have some sort of capability for supporting
modules outside /usr/lib/python/site-packages. In the end, I suspect it
would be just as easy or easier to re-structure mailman to put it's modules
in /usr/lib/python/site-packages. I suspect the above NOTE provides a hint
to make this easier.

> Hope you can implement this missing bits for 0.x ;-)

have you been looking at 0.3?


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