[Distutils] Setuptools' goal in rpm/deb-based systems

[Kevin Dangoor]

On 12/29/05, Jeff Pitman <jeff.pitman at gmail.com> wrote:
> This may have been discussed ad nauseum already, but as I tried to
> package turbogears for Fedora/CentOS, I thought I'd throw in 2 cents.

Hey, great! I'm sure many will appreciate the effort!

> I see that --single-version-externally-managed has been added as an
> option so that .deb/.rpm packaging can take advantage of that relying
> upon apt/yum/smart to take care of business. Hopefully, this will be
> pushed out soon. (Because turbogears script generation is not trivial
> to package. I think I'll just include a generated script as one of the
> Sources, for now.)

Note that TurboGears 0.9 absolutely needs to run as a proper egg.
(When you say you're including the generated script as part of the
sources, I'm not sure if that means that you're bypassing the egg
packaging entirely...)

> I think the goal for setuptools on rpm/deb-based systems should focus
> on getting $HOME setup and managed correctly for packages not provided
> by the system. For example, if I had an ISP which provided python2.4,
> but not TurboGears, then I could use .egg to manage a setup in $HOME
> to use the packages correctly. Currently, -d/-s and other options can
> be used. But, if the user isn't root, maybe it should be the default
> behavior: install and manage in $HOME.

Setting things up in $HOME is definitely a good thing, and doesn't
take very much effort. I hope more ISPs will do so (and it's something
I'm working on with TurboGears hosting providers).

> Also, are there efforts to detect if a package is already installed?
> For example, if "python-sqlobject" is installed, can setuptools detect
> the lib if the install_requires has "SQLObject"? I think peering
> between .egg and .deb/.rpm to be a difficult problem. So, having it
> all or nothing would be a cleaner policy. .deb/.rpm to manage /usr
> installed packages/modules and .egg to manage $HOME installed
> packages.

The problem is with the missing metadata. setuptools doesn't know what
version of SQLObject that is, and TurboGears most definitely requires
0.7 and up. I think the goal is ultimately to have system-installed
.debs/.rpms that are also eggs (with the proper metadata). TurboGears
0.9 makes use of setuptools' extension mechanism which is why the egg
metadata needs to be available.

Kevin