[R-sig-Debian] problem with `viridis` on Ubuntu 20.04

[Dirk Eddelbuettel]

On 30 April 2020 at 16:40, Samuele Carcagno wrote:
| after some further investigation I found out that the issue was related 
| to some calls to the `solve` function in `make.rgb`, and indeed running 
| `example(solve)` would hang my R session. After I changed the default 
| BLAS with:
| 
| sudo update-alternatives --config libblas.so.3-x86_64-linux-gnu
| 
| the problem disappeared. The BLAS output of `sessionInfo` now that 
| `solve` is working is:
| 
| Matrix products: default
| BLAS:   /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0
| LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3
| 
| while before when `solve` was not working it was:
| 
| Matrix products: default
| BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3
| LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/liblapack.so.3
| 
| so it seems the issue is with the Ubuntu package `libopenblas0-pthread` 
| and has nothing to do with R. I don't know why openblas-pthread was the 
| default BLAS on my system.

That is most helpful! It could potentially affect lots of other users too.

And on the aforementioned rocker/r-ubuntu:20.04 image, if upgrade to
libopenblas-dev I get it too:

  root using d9a07e9f0e5f:/work# apt install libopenblas-dev
  Reading package lists... Done
  Building dependency tree       
  Reading state information... Done
  The following additional packages will be installed:
    libopenblas-pthread-dev libopenblas0 libopenblas0-pthread
  The following NEW packages will be installed:
    libopenblas-dev libopenblas-pthread-dev libopenblas0 libopenblas0-pthread
  0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
  Need to get 13.7 MB of archives.
  After this operation, 153 MB of additional disk space will be used.
  Do you want to continue? [Y/n] 

and then 'example(solve)' hangs at

  sh8 <- solve(h8)

Not good at all.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd using debian.org