Hello Andres,
It finally failed with a core on 8f72bba, in llvm_shutdown, AFAIKS in a free while doing malloc-related housekeeping.
My guess is that there is an actual memory corruption somewhere. It is unobvious whether it is in bleeding-edge llvm or bleeding-edge postgres though.
The issue is non-deterministically triggered in contrib checks, either in int or ltree, but not elsewhere. This suggests issues specific to these modules, or triggered by these modules. Hmmm…
I've just launched a run with valgrind enabled. -- Fabien.
