spkg-configure for GSL

[dimpase]

Depends on #27870

CC: @embray @kiwifb @isuruf @mkoeppe

Component: build: configure

Work Issues: install modified gsl.pc

Author: Dima Pasechnik

Branch/Commit: a180599

Reviewer: Isuru Fernando

Issue created by migration from https://trac.sagemath.org/ticket/28879

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

e5c91db	update pkgconfig to v1.5.1. See trac #28883
1720b38	a bare minumim openblas config
925266b	use openblas.pc for blas and lapack, don't require atlas is to be used
b89df80	move blas handling to build/pkgs/
6341576	create cblas.pc link, too, not only blas and lapack
3a95431	spkg-configure for gsl

[sagetrac-git]

Changed commit from f8833aa to 3a95431

[isuruf]

comment:4

Did you check this with an underlinked GSL (A blas library is not linked in) or a fully linked one like Sage's GSL?

[sagetrac-git]

Changed commit from 3a95431 to 137c972

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

137c972

typo in variable name

[dimpase]

comment:6

Replying to @isuruf:

Did you check this with an underlinked GSL (A blas library is not linked in) or a fully linked one like Sage's GSL?

Only on debian and gentoo, where it's linked to its own gslcblas

[kiwifb]

comment:7

Replying to @dimpase:

Replying to @isuruf:

Did you check this with an underlinked GSL (A blas library is not linked in) or a fully linked one like Sage's GSL?

Only on debian and gentoo, where it's linked to its own gslcblas

Not on my gentoo box, but that would be the default. In any case neither debian or gentoo will ship it underlinked. I don't think any major distro ship underlinked libraries. OK as much as they can help it. Stuff that people build themselves is another story

[isuruf]

comment:8

What happens when gslcblas and openblas are both linked in?

[kiwifb]

comment:9

A bit pathological, but basically nothing visible until you test something with a high precision where there can be divergences between the two.
If you run GSL test suite with openblas rather than gslcblas you'll get failures of the numerical noise kind.

Honestly, I am not sure which one would be used. My guess would be the first one on the list of libraries linked.

[isuruf]

comment:10

Okay. Another concern is when system's gsl.pc is used by downstream packages, they'll be linking to gslcblas instead of openblas, but sage's gsl.pc would link the downstream package to openblas.