Re: [gentoo-dev] Re: Gentoo Prefix: on EPREFIX, ED and EROOT inside ebuilds

[Fabian Groffen <grobian@gentoo.org>]

On 26-11-2009 12:36:47 +0000, Duncan wrote:
> > I think there's unfortunately no simple way to tell what should be in
> > and what unfortunately has to be out.  It depends a lot on the host
> > system.  I feel -- but I can't back this up with hard evidence -- that
> > it are usually the libs that are not in *DEPEND that can only be
> > available in the host system.  Basically because they usually are part
> > of the libc, which we assume to be installed.
> > 
> > 
> > [1] http://dev.gentoo.org/~grobian/prefix-quiz
> 
> Thanks again.  That quiz was particularly enlightening (to this gentoo, 
> not prefix, user) on the type of stuff you think about, as a part of what 
> prefix /does/.

The following bug is a classical example of something which just happens
to work by accident, but is broken.  It also illustrates what kind of
changes people can expect to have to be made to their ebuilds to get
them to work for Prefix:

  http://bugs.gentoo.org/show_bug.cgi?id=293901

Because the ebuild gives a direct pointer to a place in the filesystem,

  --with-apr=/usr/bin/apr-1-config

the ebuild needs a change such that it points to the corresponding place
in the offset-prefix installation, e.g. under "${EPREFIX}".

  --with-apr="${EPREFIX}"/usr/bin/apr-1-config

When this variable is empty, there's obviously no change to the
behaviour of the ebuild.


-- 
Fabian Groffen
Gentoo on a different level