cubicweb-worker #7423207 provide reasonable info about the cause of worker death [done]
Known causes, such as instance shutdown (debug/service mode), task abortion, or byzantine failures, should be distinguishable easily.
|closed by||#7ad4184229e9 Add an attribute on workers to record the probable cause of its end-of-life.|
|patch||Add an attribute on workers to record the probable cause of its end-of-life. [applied]|