The backtraces you captured look like the query is not "hung", it's
just computing away.
He mentioned earlier that the query was hung as 'active' for 8 hours and on.
incase this is due to bad plan,
@Jurrie Overgoor is it also possible for you to run manually
`vacuumdb -a -v` from the terminal, each time before you run your test suite for some runs, do you still get the same issue?
I have a feeling repeated runs may have caused a lot of bloat on some tables which might have not been reclaimed by autovacuum runs.
