Implement the solution for the Ubuntu/OpenBLAS problem in the GH Actions workflow

[moazzammoriani]

For #341 , conf-openblas fails to install in the GH actions workflow. This happens because of a known issue. The work-around is to build OpenBLAS from source--as shown in this Dockerfile. I'm not sure how to get the necessary permission in the GH actions workflow to use the ldconfig command. Any help would be appreciated.

[shakthimaan]

how to get the necessary permission in the GH actions workflow to use the ldconfig command.

You can add the build steps to the GitHub Actions main.yml file (https://github.com/ocaml-bench/sandmark/blob/main/.github/workflows/main.yml) with a PR.

What error or permission are you facing with ldconfig?

[moazzammoriani]

This is the failure that I'm talking about: https://github.com/ocaml-bench/sandmark/runs/6807710255?check_suite_focus=true. And this is the line that makes it fail: https://github.com/ocaml-bench/sandmark/pull/341/files#diff-7829468e86c1cc5d5133195b5cb48e1ff6c75e3e9203777f6b2e379d9e4882b3R45. Is it possible to obtain the necessary permissions to run this command?

[shakthimaan]

OpenBLAS can be installed locally without having to require sudo. The Installation Guide provides the required details at https://github.com/xianyi/OpenBLAS/wiki/User-Manual. For example, one can build and install OpenBLAS on Ubuntu 20.04.3 LTS using the following commands:

$ wget https://github.com/xianyi/OpenBLAS/releases/download/v0.3.20/OpenBLAS-0.3.20.tar.gz
$ tar xzvf OpenBLAS-0.3.20.tar.gz 
$ cd OpenBLAS-0.3.20/
$ make
$ make PREFIX=/tmp/openblas install

The test_blas_open.c file can be compiled using:

$ gcc -o test_blas_open test_blas_open.c -I /tmp/openblas/include -L /tmp/openblas/lib -lopenblas -lpthread

The LD_LIBRARY_PATH environment variable needs to be updated as follows:

$ export LD_LIBRARY_PATH=/tmp/openblas/lib:$LD_LIBRARY_PATH

The binary can finally be executed as shown below:

$  ./test_blas_open 
11.000000 -9.000000 5.000000 -9.000000 21.000000 -1.000000 5.000000 -1.000000 3.000000

Avoid sudo, unless it is absolutely necessary.