I thought I would mention this issue on the mailing list to make it easier for people to search for if they have issues with their spank plugin after upgrading to Slurm 20.02.2 or newer.
Seems that the slurm_spank_job_prolog (or epilogue) functions are not found or called if you don't have "PlugstackConfig" explicitly defined in your slurm.conf (ie: you depend on the default value). This bug report has some details https://bugs.schedmd.com/show_bug.cgi?id=9081#c17 thanks -k
