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

[Dirk Eddelbuettel]

What blas/lapack -dev libraries do you installed when you build?  I varied
this over the two+ decades for the Debian build but any consistent pair of
LAPACK and BLAS should work. From the aforementioned build log:

Get: 150 http://ftp.us.debian.org/debian sid/main amd64 libblas3 amd64 3.11.0-2 [149 kB]
Get: 151 http://ftp.us.debian.org/debian sid/main amd64 libblas-dev amd64 3.11.0-2 [158 kB]
[...]
Get: 227 http://ftp.us.debian.org/debian sid/main amd64 liblapack3 amd64 3.11.0-2 [2323 kB]
Get: 228 http://ftp.us.debian.org/debian sid/main amd64 liblapack-dev amd64 3.11.0-2 [4631 kB]
[...]
Setting up libblas3:amd64 (3.11.0-2) ...

update-alternatives: using /usr/lib/x86_64-linux-gnu/blas/libblas.so.3 to provide /usr/lib/x86_64-linux-gnu/libblas.so.3 (libblas.so.3-x86_64-linux-gnu) in auto mode

[...]
Setting up liblapack3:amd64 (3.11.0-2) ...

update-alternatives: using /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3 to provide /usr/lib/x86_64-linux-gnu/liblapack.so.3 (liblapack.so.3-x86_64-linux-gnu) in auto mode


I use

  libblas-dev, liblapack-dev

as the Build-Depends in the chroot.  I think these are the generic one, they
provide a fallback. (And run-time I think I am defaulting to OpenBLAS most of
the time.)


FWIW I always found

  --with-blas="-lblas"
  --with-lapack="-llapack"

a little suspicious, but maybe that is just me if this works for you we are
where we wanted to be and all is good?

Dirk

-- 
dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org