Re: Is there a way to positively, uniquely identify which Debian release a program is running on?
On Fri, Jun 01, 2007 at 02:51:27PM -0400, Kris Deugau wrote:
> Santiago Vila wrote:
> > That's the fundamental mistake I see here: We should not be telling
> > programs what "release" they are running to begin with. We do not try
> > to make packages to work under the assumption that they will run
> > "on a sarge system" or "an etch system". Instead, we try to make them work
> > as far as their dependencies are met.
> ... which means what, exactly, if my program expects
> /usr/lib/apache2/suexec but the system (stock Debian sarge) only has
> /usr/lib/apache2/suexec2? Or vice versa for etch? (Or more accurately,
> I need to know in advance - in this case, at package build time - which
> name suexec gets so that the Apache config fragment I drop in doesn't
> break.)
And what do you do when the system says it's "sarge", but the user trying to
install your package is using a backport of apache2.2 because they needed
some new feature, so suexec is under the new name?
What do you do when the user installs the "sarge" version of your package,
and then does a partial upgrade to etch? Heck, what do you do when the user
installs the "sarge" version of your package, and does a *full* upgrade to
etch? There's no channel by which your package is going to be notified of
the changes to the versions of other installed packages.
Package dependencies are the right answer here, not distribution-based
guessing.
> OK, so if it's one file I can munge in a solution that checks
> at install time or something. What about a case where there are
> *hundreds* of little things like this with complicated subcases?
Then you have a difficult task ahead of you to create a package that works
for your users. But it's quite unrealistic that you will ever have a case
of hundreds of little, *independent* things that differ between dists that
you need to check for. Your hundred little changes are probably reducible
to three or four versioned dependencies.
> (Mildly amusing sidenote to this discussion: I'm finally convincing the
> senior systems guy that Packages Are Good, and now developers for the
> upstream OS seem to be telling me Packages Are Useless, because I can't
> even count on a critical dependency being installed via the package
> system. <g>)
You can depend on it if you're using dependencies right.
--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
vorlon@debian.org http://www.debian.org/
Reply to: