Re: [gentoo-dev] reconciling new-style virtuals with overlays, was: RDEPENDing on packages from overlays?

["Chí-Thanh Christopher Nguyễn" <chithanh@gentoo.org>]

Ciaran McCreesh schrieb:
> On Sat, 23 Apr 2011 16:47:37 +0200
> Chí-Thanh Christopher Nguyễn <chithanh@gentoo.org> wrote:
>   
>> What I propose solves the problems that old-style virtuals introduce
>> in dependency resolution.
>>     
> Not really, because it means we'd have to keep the nasty old code around
> forever. If we just do away with the things entirely instead then we
> can pretend they never existed (like we did for ? : dependencies).
>   

We can mostly pretend that they never existed. PROVIDE will only be
relevant during the installation phase.

>> What other problems do they cause?
>>     
> DEPEND=">=virtual/blah-2"
>
> DEPEND="virtual/blah[foo]"
>
> DEPEND="!virtual/that-i-provide"
>
> PROVIDE="not-a/virtual"
>   
Would be ignored during dependency calculation and become
not-a/virtual-<version> in package.provided later.
> best_version virtual/blah
>
> The full VDB load required to figure out whether or not a virtual is
> installed

Problems I had indeed not taken into account are !virtual/foo
dependencies and USE flags in package.provided (not allowed yet, bug
142941). But the former are also not going to work any more if new-style
virtuals are used instead of old-style, as you block only the virtuals
and not their providers.

If the USE flag problem is considered a show-stopper, then I have to
take back my proposal until bug 142941 is fixed.


Regards,
Chi-Thanh Christopher Nguyen