Investigate recent abi-api-compliance CI job failures
The abi-api-compliance CI job seems to be failing sometimes, e.g. https://gitlab.com/tango-controls/cppTango/-/jobs/4115947623.
What is odd is that there is no output at all from the script, which suggests it is failing early on. My suspicion is that the job fails when the merge branch is some number of commits behind main. Perhaps something like
old_revision=$(git merge-base --fork-point origin/${CI_TARGET_BRANCH} HEAD)
is failing in this case.