Re: Updating both Perl and Perl Modules from a binary repository

[David Holland <dholland-pkgtech%netbsd.org@localhost>]

On Thu, Apr 19, 2012 at 10:03:35PM +0200, Joerg Sonnenberger wrote:
 > On Thu, Apr 19, 2012 at 07:51:41PM +0000, David Holland wrote:
 > > On Thu, Apr 19, 2012 at 03:33:41PM +0200, Edgar Fu? wrote:
 > >  > > What does "pkg_add -u perl p5-Foo p5-Bar" say?
 > >  >
 > >  > I don't remember exactly, but in essence "this doesn't work".
 > >  >
 > >  > I think, it was that it couldn't install perl-5.14 because p5-*
 > >  > depended on perl<5.14. And it couldn't update p5-Foo because that
 > >  > would imply updating perl from 5.12 to 5.14, whereas p5-Bar
 > >  > depended on perl<5.14.
 > >  >
 > >  > My impression was that pkg_add failed to realise that if if would
 > >  > do *all* the updates at once, the result would be consistent, but
 > >  > bailed out because there was no path of *gradually* performing the
 > >  > updates that would, in each step, keep the dependencies fulfilled.
 > > 
 > > That would be a bug.
 > 
 > I would disagree. The core issue here is that you can't do this update
 > with "local" changes. To keep the set of installed packages consistent,
 > you have to remove all Perl packages, update Perl and re-install them.
 > This case (having to deinstall something else first) is exactly what IMO
 > should *not* be the task of pkg_add, but a higher level tool. The
 > existing logic to recursively update dependencies is already borderline,
 > but forcing logic for even more complicated cases is not useful.

Nearly every successful binary package system I can think of supports
transactional updates of groups of packages at this level, to handle
precisely this problem.

-- 
David A. Holland
dholland%netbsd.org@localhost