Re: Finer Extension dependencies

On tor, 2012-03-29 at 09:51 +0200, Dimitri Fontaine wrote:
> I don't want to introduce version dependency, because I don't think we
> need it. If you want to compare what we're doing here with say debian
> packaging, then look at how they package libraries. The major version
> number is now part of the package name and you depend on that
> directly.
>
> So let's take the shortcut to directly depend on the “feature” name.
>
> For a PostgreSQL extension example, we could pick ip4r. That will soon
> include support for ipv6 (it's already done code wise, missing docs
> update). If you want to use ip4r for storing ipv6, you will simply
> require “ip6r” or whatever feature name is provided by the extension
> including it.

Note that in Debian, virtual package names (the ones you give in the
Provides line) are effectively centrally managed. Most are specified by
the policy, the rest are managed between the affected packages. This
rests on the assumption that very little outside packaging that deviates
from the official Debian packaging goes on.

Since we don't have any central coordinator or authority of that kind,
we need to design the system differently.

At the very least, I would suggest that feature names are per-extension.
So in the above example you could depend on something like "ipv4[ipv6]".