Hold on, I've now encountered the same issue for another service, but with signals :)
In servicedir's finish: s6-permafailon 120 2 1-255,SIGBUS,SIGSEGV exit 0 svc -t servicedir svc -t servicedir 2020-11-17 19:20:24.465424531 s6-permafailon: info: PERMANENT FAILURE triggered after 2 events involving signal 15 in the last 120 seconds s6-svdt servicedir | s6-tai64nlocal 2020-11-17 19:19:30.449842687 signal SIGTERM 2020-11-17 19:20:24.419594225 signal SIGTERM Back to s6-permafailon.c: the sigset_t sigs is not initialized either... Looks like it needs a call to sigemptyset(). Hope this helps :)