Andreas Seltenreich <seltenreich@gmx.de> writes:
> when fuzz testing master as of c1543a8, parallel workers trigger the
> following assertion in ExecInitSubPlan every couple hours.
> TRAP: FailedAssertion("!(list != ((List *) ((void *)0)))", File: "list.c", Line: 390)
> Sample backtraces of a worker and leader below, plan of leader attached.
> The collected queries don't seem to reproduce it.
Odd. My understanding of the restrictions on parallel query is that
anything involving a SubPlan ought not be parallelized; and this query
doesn't seem to get parallelized when I try it. It seems like what you're
seeing is that sometimes that restriction fails to be checked, but how
could that happen?
regards, tom lane