VM fetch finished but never returned

Logging this for future investigation:

I just downloaded an image and it finished successfully (according to the standard output at least) but the command did not exit.


Notice the logs say 22m but the time it took for my terminal to run the command (in the prompt) is 49m. So it hung for ~25m till I pressed `Ctrl-C`.

Start by reproducing an image download and compare the standard-output completion time with the terminal prompt returning. Investigate what remains active after the fetch reports success; done means the command exits normally without requiring Ctrl-C and the reported timing is consistent.

Written by the indexing model from the issue text.