[Distutils] Twisted packaging in Debian

[Jean-Paul Calderone]

On Wed, 08 Oct 2008 00:03:16 +0200, Josselin Mouette <joss at debian.org> wrote:
>Le mercredi 08 octobre 2008 à 08:44 +1100, Ben Finney a écrit :
>> Josselin Mouette <joss at debian.org> writes:
>>
>> > About this issue, I still think you need to version your plugins
>> > directory if the plugins are not compatible across versions.
>>
>> You've referred to this a few times now without explaining exactly
>> what you expect the developer to do. So, just in case:
>>
>> I presume you mean that, in the case where a program's plugins are not
>> compatible with plugins for previous versions of the same program, the
>> developer should always seek (and attempt to install) plugins for
>> version N in a differently-named directory from plugins for version M
>> and version P.
>>
>> That is, that a directory expected to contain plugins for version N
>> should contain *only* plugins for version N, and never for other
>> versions.
>
>Yes. Sorry for omitting this detailed explanation.

What if we consider the scenario without two different versions?  The
plugin duplication issue happens if you have a site-wide installation
of Twisted X.Y and an extra (eg, per-user) copy of Twisted X.Y, the
same version, explicitly in PYTHONPATH.

Versioning the plugin directory wouldn't help here, because both copies
would appear to be the right version for whichever instance of the install
gets used.

It might be possible to avoid duplication by inspecting the names carefully
and avoiding loading anything that looks like it was already loaded.  But I
can still think of problem cases - the site-wide installation has plugins X,
Y, and Z and my personal installation has plugins A, B, and C, and I use my
personal installation with the express intent of not having X, Y, and Z made
available.  If the site-wide plugins directory is considered, then I get all
6 - not what I wanted.

Jean-Paul