[R-sig-Debian] custom built R will not change BLAS/LAPACK with update-alternatives

[Ramon Diaz-Uriarte]

On Sat, 30-December-2023, at 20:24:49, Dirk Eddelbuettel <edd using debian.org> wrote:
> On 30 December 2023 at 21:57, Ivan Krylov wrote:
> | On Sat, 30 Dec 2023 18:37:06 +0100
> | Ramon Diaz-Uriarte <rdiaz02 using gmail.com> wrote:
> | 
> | >  configure: searching for an external BLAS
> | > configure: searching for BLAS in default libraries
> | > checking for dgemm_... no
> | > configure: searching for OpenBLAS
> | 
> | The code implementing this logic is in m4/R.m4, starting around line
> | 2600. If --with-blas is given without an argument, the configure script
> | goes searching for various BLASes. It happens to try -lopenblas before
> | -lblas, so that's what ends up being linked.
>
> Yes. My hint about the build-dependencies aimed at that.
>  
> | Does it help to use --with-blas=blas or --with-blas=-lblas so that the
> | configure script doesn't try to detect it automatically?
>
> I used to set it that way (still commented out in debian/rules) but it is not
> needed AFAICT provided one has suitable packages to build against installed
> (in the chroot, or container, or on the machine).

But I do not see how it can work if the machine has, in addition to the build dependencies, OpenBLAS or ATLAS: it should pick those first (and it does for me), and then those no longer change when changing update-alternatives.

Anyway, the solution for me is easy enough (use --with-blas=-lblas).


R.

>
> Dirk


-- 
Ramon Diaz-Uriarte
Department of Biochemistry, Lab B-31
Facultad de Medicina 
Universidad Autónoma de Madrid 
Arzobispo Morcillo, 4
28029 Madrid
Spain

Phone: +34-91-497-2412

Email: rdiaz02 using gmail.com
       r.diaz using uam.es
       ramon.diaz using iib.uam.es

https://ligarto.org/rdiaz