When I tried to generate a dump set (managewiki settings, xml, and images), managewiki settings and images dump generation went through, but xml dump did not finish in time so I deleted it thrice and retried.
The JobQueue count increased by 1 for a minute or two, and then dropped back to 0 while the job itself is "Queued" and dump never completed.
{ "batchcomplete": "", "query": { "statistics": { "pages": 462, "articles": 107, "edits": 3690, "images": 25, "users": 82, "activeusers": 2, "admins": 2, "jobs": 1, "queued-massmessages": 0 } } }