Re: [gentoo-osx] prefix ebuild's api suggestion

[Brian Harring]

On Fri, Jan 27, 2006 at 08:10:41PM +0100, Dirk Sch??nberger wrote:
> > > > Another possible feature in the future (not finished thinking about
> > > > yet)
> > > > could be to have portage install each (non-system-)package into a
> > > > separate prefix within its domain, without need to change prefix-api.
> > > > This could help ebuild-devs to detect unknown dependencies, which are
> > > > not found implicitly if not specified at configure-line.
> > > > Well - only for a testing system, and to be enabled explicitly
> > > > by setting FEATURES.
> > >
> > > This probably isn't as crazy as you might think. With ROOT, and a
> > > little more work on PREFIX, it should just be a matter of setting
> > > these appropriately on a per package basis. The other possible use
> > > for this would be creating package bundles with complete dep trees
> > > suitable for distribution.
>
> >  Wow, ideas over ideas, and they all are conceivable!
>
> Because we are at strange ideas, would it be possible to introduce
> something like
> $PREFIXES, where this is a list of directories, say
>
> $PREFIXES=/:/gentoo
>
> If I want to emerge a package, the package should be installed into the
> first matching
> PREFIX
> If problems occur, say because there exist a un-manged version of some
> package, the prefix is black-listed for this packaage, and the next
> directory is choosen.

Portage currently doeesn't really track prefix in the prefix branch; 
it's a compile time directive that just makes portage build stuff with an 
offset.  Getting into what you're requesting, means portage will have 
to be aware of the prefix (and capable of swiveling it), which is 
getting into the domain side of things.

That's getting into interdomain crap; current intentions (and they're 
just intentions since I haven't yet written any interdomain code) is 
that you define the domain you wish to manage; this includes a PREFIX 
definition.  During resolution, that domain reaches up to the parent 
domain (PREFIX=/), and queries it for what's available and where; 
that's how it would handle satisfying a python dep when you're 
targetted prefix is home (fex).  What you seem to be asking is the 
ability to state "I want this merged, globally if possible, else in a 
prefix", which is a resolver decision, and reliant on the domain 
concept.


> This black-listing can also be done by a user.
Currently, 
EAPI="prefix"
means that the ebuild can be installed to *any* prefix (implicitly /); 
the change you're requesting (imo) is beyond the focus of the prefix 
branch.  Prefix branch is strictly having ebuilds merged to an alt 
prefix- selection of which domain/prefix to merge to is a bit higher 
up in the design of things.

~harring