Gentoo Archives: gentoo-science

From: "Sébastien Fabbro" <bicatali@g.o>
To: gentoo-science@l.g.o
Subject: Re: [gentoo-science] [PATCH 00/10] alternatives-2.eclass updates
Date: Tue, 21 Jan 2014 22:46:35
In Reply to: Re: [gentoo-science] [PATCH 00/10] alternatives-2.eclass updates by Reinis Danne
1 On Tue, Jan 21, 2014 at 1:30 PM, Reinis Danne <rei4dan@×××××.com> wrote:
3 >
4 >
5 > Ok, that is different issue. The question is whether we want,
6 > e.g., eselect blas be build time only or also runtime setting.
7 >
8 > If we use provider specific sonames, then the program will use
9 > whatever provider was selected at build time even if different
10 > provider is set afterwards. Thus it is build time only setting,
11 > with the caveat that package has to be rebuilt if selected
12 > provider is removed (preserved-libs should catch this).
13 >
14 > ⬑ This is how it is now in the overlay.
15 >
17 One other advantage of keeping the generic names is also that maintainer
18 would not have to modify the ebuild for packages to link with the selected
19 provider. Most blas dependent packages assume there is /usr/lib/
21 Some applications (I can see armadillo, scamp) actually use the
22 atlas-specific routines clapack_* routines.
23 We could aim at keeping both the library soname and filename as close to
24 upstream, and add an option to the alternative framework to create a
25 ldscript with a generic soname and filename, turned on for blas and cblas
26 at least.
28 As a user, I don't particularly enjoy rebuilding octave, ROOT, R, or the
29 scipy stack. @preserved-rebuild is more a hack than a feature.
30 I don't know how many people actually switch providers, besides a first
31 benchmark test. My guess is probably not many given the burden of
32 re-compiling all the reverse dependencies and the previous fragility of the
33 system.
35 Sebastien