On Fri, 30 Oct 2015 23:40:28 +0100
hasufell <hasuf...@gentoo.org> wrote:
> On 10/30/2015 10:16 PM, Anthony G. Basile wrote:
> > On 10/30/15 3:35 PM, hasufell wrote:
> >> On 10/30/2015 06:55 PM, Michał Górny wrote:
> >>> We have no way of saying 'I prefer polarssl, then gnutls, then
> >>> libressl, and never openssl'.
> >> I don't think this is something that can be reasonably supported
> >> and it sounds awfully automagic. And I don't see how this is
> >> possible right now, so I'm not really sure what you expect to get
> >> worse.
> >>
> >> E.g. -gnutls pulling in dev-libs/openssl is not really something
> >> you'd expect. If we go for provider USE flags, then things become
> >> consistent, explicit and unambiguous. The only problem is our
> >> crappy implementation of providers USE flags via REQUIRED_USE.
> >>
> > I'm not sure what mgorny has in mind, but the problem I see with
> > saying I want just X to be my provider system wide is that some
> > pkgs build with X others don't, other pkgs might need a different
> > provider. So it might make sense to order them in terms of
> > preference: X1 > X2 > X3 ... and then when emerging a package, the
> > first provider in the preference list that works is pulled in for
> > that package.
>
> Isn't that basically what the proposal B already was, except that we
> don't use REQUIRED_USE for it but some sort of pkg_setup/pkg_pretend
> function? I don't see how those ideas even conflict.
>
Well, not exactly. If I understood them right, mgorny and blueness are
asking for a user-supplied preference list (e.g. "I want packages to
link with libressl if possible, gnutls otherwise"), not an
ebuild-supplied preference list ("This package prefers gnutls, but
openssl is also supported").
Side note: These ebuild-side preferences are used by some ebuilds (e.g.
cyrus-sasl, it uses gdbm if both gdbm and berkdb use flags are
enabled), but for ssl, we might want to specify "REQUIRED_USE = ^^
(..)" so it's possible to use USE dependencies in order to avoid
namespace conflicts. If there's no REQUIRED_USE,
"somelibrary[libressl]" might be satisfied even though somelibrary is
actually linked to openssl.
--
Regards,
Luis Ressel
