Adding the `--include-easyblocks-from-pr` prevents EasyBuild from locating hooks in relative paths

[gkaf89]

Affected EasyBuild version: 5.2.0

Description

We set the hooks option to relative paths in our configuration (.cfg) scripts. Adding the --include-easyblocks-from-pr option seems to prevent EasyBuild from correctly interpreting the relative paths. The issue in reproducible with terminal options:

0 [gkafanas@aion-0256 easybuild-stack](10913830 1N/8T/8CN)$ eb --include-easyblocks-from-pr=4043 --hooks=${PWD}/configuration/hooks/ulhpc.py --search GROMACS-2025.2
== easyblock pythonpackage.py included from PR #4043
== found valid index for /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs, so using it...
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2-foss-2025a.eb
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2-foss-2025b.eb
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2-lfoss-2025b.eb
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2-lmpflf-2025b.eb
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2_fix-sample_restraint-mpich-launch.patch
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2_gmxapi-remove-builddependencies.patch
 * /opt/apps/easybuild/systems/aion/rhel810-20260107/2025a/epyc/software/EasyBuild/5.2.0/easybuild/easyconfigs/g/GROMACS/GROMACS-2025.2_workaround-arm-sve512.patch
0 [gkafanas@aion-0256 easybuild-stack](10913830 1N/8T/8CN)$ eb --include-easyblocks-from-pr=4043 --hooks=configuration/hooks/ulhpc.py --search GROMACS-2025.2
ERROR: Specified path for hooks implementation does not exist: configuration/hooks/ulhpc.py

Work around

The related --include-easyblocks is not affected by this issue.