seff-array.py:509
req_mem = float(data[0].split("|")[4][0:-1]) # remove M unit, convert to float
An extra character is being returned by sacct in the ReqMem field. Instead of "1M" it returns "1Mc" or "1Me" I haven't identified the cause for this in sacct but created a workaround by changing "-1" to "-2". A more reliable fix would be to strip alpha characters prior to converting to float.
SLURM 20.11.9-1.el7