[arch-general] Depends on foo-bar=10.0-3

[Paul Gideon Dann]

On 14 August 2017 at 13:48, Ralf Mardorf <silver.bullet at zoho.com> wrote:

> On Mon, 14 Aug 2017 14:03:45 +0200, mpan wrote:
> >> why does a package from official repositories mentions what version
> >> of a dependency is required?
> >Because it may be that it is working only with that particular
> >version.
>
> That doesn't explain why it is needed or in any way useful for a package
> provided by official Arch repositories? Partial upgrades are
> unsupported [1]. Actually it could be vary annoying, if packages now
> start including the version of a dependency. I didn't notice that
> packages mention dependency versions for at least the last 4 years [2].
> It's not the only dummy package I'm using for at least that long.
>

Yes, partial upgrades are unsupported, but in practice this still happens,
usually not deliberately. For instance, I will quite often do a "pacman -S
<package>" without doing a full system update first, assuming that
*probably* nothing important has changed since the last update. It's a
sloppy practice, but humans cut corners: it happens. When a plugin relies
on a potentially unstable ABI (not many applications offer stable ABIs),
specifying that the plugin package requires that exact version of the
application will ensure that mistakes like this don't happen.

If I see an error like "package x requires y=1.2.3" when installing a
package, the first thing I'll try is a system update, an obscure segfault
is avoided, and everyone's happy. So the failsafe does the job. It's good
defensive practice by the packaging team, I think.

Paul