Arch + MKL + Eigen incompatibility

[matekelemen]

Due to a bug in MKL < 2025.1 that manifests in newer Eigen versions (since #13887 was merged), the LinearSolversApplication fails to compile on Arch-based distros.

This is because MKL's version in the AUR is still 2025.0.1-3.

Apart from downgrading Eigen (which I don't support), there's nothing we can do about this in our repo. Arch users should either compile without MKL support or manually install a newer MKL version until the AUR gets updated.

[RiccardoRossi]

Ouch...how often is mkl updated?

[loumalouomega]

Ouch...how often is mkl updated?

In arch, it is strange they don't put the version the second after is published.... @roigcarlo will gte the joke

[loumalouomega]

Apart from downgrading Eigen (which I don't support), there's nothing we can do about this in our repo. Arch users should either compile without MKL support or manually install a newer MKL version until the AUR gets updated.

I will go for the second option.

[matekelemen]

Yes, the whole selling point of Arch is that its packages are as up-to-date with their sources as possible, so it's extremely weird that MKL packages have been out of date for half a year.

Another possible solution would be to provide an option for users to rely on a custom Eigen installation (same as we require boost) instead of the one we provide. This would make a lot of sense especially if they also depend on Eigen in their own private applications.

[roigcarlo]

Yes, the whole selling point of Arch is that its packages are as up-to-date with their sources as possible, so it's extremely weird that MKL packages have been out of date for half a year.

I think the Intel-OneAPI-mkl package is maintained by intel, that would explain a lot of things (I am not implying anything). But I also would agree to allow to compile against a custom MKL instalation (its already possible if you play a bit with the MK_ROOT var, but anyway....)