Re: [gentoo-dev] [RFC] Policy for migrating library consumers to subslots

[Kent Fredric]

On 26 September 2013 19:53, Michał Górny <mgorny@g.o> wrote:

> How do we handle packages which install multiple libraries? I'm afraid
> forcing such a policy and/or hurrying developers to adapt will only
> cause more of poppler-like issues to occur.
>

Can you give a an example package which:

- installs multiple libraries
- has an ABI that may change for only one of those libraries
- it is sane / plausible to expect one downstream dependent *not* to
forcibly rebuild as a result of a chane in one of those libaries
- it is sane / plausible to expect a different downstream to forcibly
rebuild as a result of changes in one of those libraries

I'm not saying they don't exist, but having reference cases would help
discussion.

I just don't see Gentoo really supporting such a scheme in the near future,
its rather complicated, you'd possibly need to have a "provides" map for
each and every ebuild*, and dependents would need to declare which specific
providers they're bound to, which would greatly complicate ebuild stuff.

And that provides map would eventually approximate a list of all files the
ebuild emits with version suffixes, which could be rather overwhelming.

This would be similar to how dependencies work on CPAN modules, where
modules are unaware of the tar.gz's their dependencies are shipped in, and
only declare dependencies on the modules in the tar.gz's, and then the
indexer maps those to the relevant packages ( which makes handling that a
bag of ferrets in gentoo without non-standard tools )


-- 
Kent