BUG: OpenBSD/amd64 7.4 doesn't build from source due to missing -lcblas

[DavidAlphaFox]

Describe the issue:

Can't install numpy through pip, because the meson can't detect the blas and lapack correctly.
And I find there aren't any blas.pc and lapack.pc under the /usr/local/lib/pkgconfig.

Reproduce the code example:

pip install numpy==1.26.1

Error message:

No response

Runtime information:

OpenBSD/amd 7.4
Python 3.10

Context for the issue:

The meson can't detect the blas and lapack in OpenBSD.

[rgommers]

Thanks @DavidAlphaFox, but we'll need a bit more info than that to be able to help. Questions:

• You do want/need to build with BLAS/LAPACK support, right?
• What BLAS and LAPACK are you using, and where are they installed?
• If it's a system package manager install, are there really no .pc files or can they only not be found?

[DavidAlphaFox]

@rgommers
Yes I need build with BLAS/LAPACK.
BLAS and LAPACK comes from OpenBSD's pkg and the are all installed under /usr/local.
The system package manager doesn't generate the .pc under /usr/local/lib/pkgconfig

[rgommers]

Thanks for the details. I'm working on a fix for this.

We don't have an OpenBSD CI job, but we do have a FreeBSD one since recently (here). That doesn't use BLAS though, so I guess we should add that.

Could you please share the exact pkg invocation for how to install BLAS and LAPACK, including headers if there's a separate -dev package? That would save some trial and error in CI.

[DavidAlphaFox]

on OpenBSD
pkg_add blas cblas lapack