Running tests on a shared cluster I noticed issue-94260-2.c failed. I only managed to reproduce de segfault by running it in a:

while /path/to/build/runtimes/runtimes-bins/openmp/runtime/test/tasking/Output/issue-94260-2.c.tmp ; do date; done

EDIT1: I ran in a Debug build
EDIT: I managed to get a coredump :) and it seems that

https://github.com/llvm/llvm-project/blob/main/openmp/runtime/src/kmp_tasking.cpp#L3236
other_pthread is 0xefefefefefefefef

Also I see some threads in the:

__kmp_fork_barrier -> __kmp_hyper_barrier_release

while others are in:

__kmpc_reduce_nowait -> __kmp_barrier -> __kmp_hyper_barrier_gather