From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amirouche Boubekki Subject: Re: Goals for 0.4 Date: Fri, 30 Aug 2013 19:40:25 +0200 Message-ID: References: <87vc2o4qwc.fsf@gnu.org> <87eh9c9sb8.fsf@gnu.org> <20130830160948.GB5927@kubera.inria.fr> Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=e89a8fb1fde6e426f504e52db891 Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:39660) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VFSgl-0004OD-Tk for guix-devel@gnu.org; Fri, 30 Aug 2013 13:40:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VFSgi-0005JT-LF for guix-devel@gnu.org; Fri, 30 Aug 2013 13:40:51 -0400 In-Reply-To: <20130830160948.GB5927@kubera.inria.fr> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org To: Cyprien Nicolas Cc: guix-devel@gnu.org --e89a8fb1fde6e426f504e52db891 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I will just add that this feature is available in nixos http://nixos.org/wiki/Nix%28OS%29_related_repositories_and_work 2013/8/30 Cyprien Nicolas > Il y a 20 heures, Ludovic Court=C3=A8s =C3=A9crivit : > > > Amirouche Boubekki skribis: > > > > > What about the possiblity to use overlays ? > > > > Could you elaborate? > > > > I hear this comes from the Gentoo jargon, but I=E2=80=99m not sure what > > that means. > > I like the idea. I'll try to elaborate myself, as a Gentoo user for > years ;-) I describe them from my own experience, official > documentation can be found there [1] > > In Gentoo, ebuilds (the files that specify how to build a package from > source) are stored in the "portage tree", which is the official > repository. The tree consists of directories, one per category, plus > one sub-directory par package, where package directories contains one > or more ebuilds, one ebuild per package version. (plus some > additional files, like patches.) > > "Portage" (the tool used to install packages from source, through the > "emerge" command) looks for ebuild in that directory, but it can also > looks from other directories which follow the same structure, those > directories are called "overlays", as they can mask packages from the > official tree, but also extend it. > > They are plenty of overlays usage: experimental packages, > user-contributed packages, locally used packages for testing purposes=E2= =80=A6 > > > However, overlay create new concerns. First, priority of overlays, if > two provide the same package-version combination, which one to choose? > If Overlay A provide Package P, which depends on Library L, not in > Overlay A but in the "base" repository, and that Overlay B provide > a newer version of Library L, which L to choose? > > Handling build failure of packages using overlays can be quite tricky > too. ;-) > > And last, how and where to "centralize" overlays, in order to give > user a tool to easily add, remove, update overlays. > > > 1. http://www.gentoo.org/proj/en/overlays/userguide.xml > > -- > Cyprien/Fulax > --e89a8fb1fde6e426f504e52db891 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I will just add that this feature is available in nixos h= ttp://nixos.org/wiki/Nix%28OS%29_related_repositories_and_work


2013/8/30 Cyp= rien Nicolas <cyprien@nicolas.tf>
Il y a 20 heures, Ludovic Court=C3=A8s =C3=A9crivit=C2=A0:

> Amirouche Boubekki <amirouche.boubekki@gmail.com> skribis:
>
> > What about the possiblity to use overlays ?
>
> Could you elaborate?
>
> I hear this comes from the Gentoo jargon, but I=E2=80=99m not sure wha= t
> that means.

I like the idea. =C2=A0I'll try to elaborate myself, as a G= entoo user for
years ;-) I describe them from my own experience, official
documentation can be found there [1]

In Gentoo, ebuilds (the files that specify how to build a package from
source) are stored in the "portage tree", which is the official repository. =C2=A0The tree consists of directories, one per category, plus<= br> one sub-directory par package, where package directories contains one
or more ebuilds, one ebuild per package version. =C2=A0(plus some
additional files, like patches.)

"Portage" (the tool used to install packages from source, through= the
"emerge" command) looks for ebuild in that directory, but it can = also
looks from other directories which follow the same structure, those
directories are called "overlays", as they can mask packages from= the
official tree, but also extend it.

They are plenty of overlays usage: experimental packages,
user-contributed packages, locally used packages for testing purposes=E2=80= =A6


However, overlay create new concerns. =C2=A0First, priority of overlays, if=
two provide the same package-version combination, which one to choose?
If Overlay A provide Package P, which depends on Library L, not in
Overlay A but in the "base" repository, and that Overlay B provid= e
a newer version of Library L, which L to choose?

Handling build failure of packages using overlays can be quite tricky
too. ;-)

And last, how and where to "centralize" overlays, in order to giv= e
user a tool to easily add, remove, update overlays.


1. http://www.gentoo.org/proj/en/overlays/userguide.xml

--
Cyprien/Fulax

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