Pass SLEPC_DIR & PETSC_DIR to SLEPc make

[Flamefire]

(created using eb --new-pr)

We do this for make of PETSc and it seems to be required. At least according to the configure output.

[Flamefire]

Test report by @Flamefire

Overview of tested easyconfigs (in order)

• SUCCESS SLEPc-3.20.1-foss-2023a.eb
• SUCCESS SLEPc-3.14.2-foss-2020b.eb

Build succeeded for 2 out of 2 (2 easyconfigs in total)
i7008 - Linux Rocky Linux 8.9 (Green Obsidian), x86_64, AMD EPYC 7702 64-Core Processor (zen2), Python 3.8.17
See https://gist.github.com/Flamefire/b42fea05c1821233bd467230aa402ebb for a full test report.

[boegel]

(created using eb --new-pr)

We do this for make of PETSc and it seems to be required. At least according to the configure output.

What are you seeing in configure output exactly that makes you conclude the proposed changes are necessary?

[Flamefire]

@gkaf89 reported that it is shown by configure and the build fails without this and succeeds with.

In my logfiles I've also seen this in my EB builds:

Configure stage complete. Now build the SLEPc library with:
make SLEPC_DIR=/dev/shm/s3248973-EasyBuild610218/SLEPc/3.20.1/foss-2023b/slepc-3.20.1 PETSC_DIR=/data/horse/ws/s3248973-EasyBuild/easybuild-rome/software/PETSc/3.20.3-foss-2023b

I'm not fully sure this resolves the issue completely as there is some weirdness but given the configure message and the similar procedure in PETSc I assume this helps and at least doesn't make anything worse.