👷 Test Apptainer / Singularity images in CI

[shnizzedy]

Related problem

Sometime around May, Singularity stopped working on CircleCI:

For reference singularity fails on CircleCI with

SINGULARITYENV_COVERAGE_FILE=.coverage.singularity${VARIANT} singularity exec -B $PWD:/code cpac-singularity-image${VARIANT}.sif /code/dev/circleci_data/test_in_image.sh

FATAL:   container creation failed: mount /proc/self/fd/3->/usr/local/var/singularity/mnt/session/rootfs error: while mounting image /proc/self/fd/3: failed to find loop device: could not attach image file to loop device: no loop devices available

Exited with code exit status 255

I tried different versions of singularity but can not get this to go away.
The images are confirmed working locally/manually so this might be a CircleCI issue.

Originally posted by @nx10 in #1916 (comment)

so we disabled those tests

Proposed feature

Either find a way to run Apptainer or Singularity on CircleCI or migrate those tests to GH Actions (if we can run Apptainer or Singularity in Actions)

Acceptance criteria

• Apptainer / Singularity images are tested in the CI

[nx10]

I tried the newest Apptainer version on CircleCI - also does not work.

+1 for migrating (if possible) to GH actions. (Unified CI, less maintenance)