As always, I found the answer 5 minutes after hitting the "send" button :-P

It turns out the Gentoo docs are wrong.  You can't do this with 
package.env.  The solution is something not mentioned in the docs. 
Putting this:

   post_src_prepare()
   {
       rm -rf "${S}"/usr/lib32/jack || die
       rm -f $(find "${S}" -name 'libjack*') || die
   }

in "/etc/portage/env/app-emulation/emul-linux-x86-soundlibs" works.


On 27/05/12 23:21, Nikos Chantziaras wrote:
> I have this in /etc/portage/package.env:
>
> app-emulation/emul-linux-x86-soundlibs soundlibs-delete-jack.conf
>
> and this in /etc/portage/env/soundlibs-delete-jack.conf:
>
> if [ "${EBUILD_PHASE}" == "src_prepare"] ;
> then
> rm -rf "${S}"/usr/lib32/jack
> rm -f $(find "${S}" -name 'libjack*')
> fi
>
> As per documentation:
>
> http://www.gentoo.org/doc/en/handbook/handbook-amd64.xml?part=3&chap=6#doc_chap3
>
>
> However, it doesn't work. What do I do?
>
> !!! Problem in 'app-emulation/emul-linux-x86-soundlibs' dependencies.
> !!! "/etc/portage/env/soundlibs-delete-jack.conf", line 1: Invalid token
> '[' (not '=') portage.exception
> ... done!
> "/etc/portage/env/soundlibs-delete-jack.conf", line 1: Invalid token '['
> (not '=')
>
>
> PS:
> What I'd really want is to define my own custom post_src_prepare()
> function. Possible?