This looks a lot like a problem between the `OBSERVED-INTERNAL-REAL-TIME-DELTA-SEC` which is a word and the new 64-bit counters.
❯ git grep observed-internal-real-time-delta-sec src/code/thread-structs.lisp: #-64-bit (observed-internal-real-time-delta-sec 0 :type sb-vm:word) src/code/unix.lisp: (sb-thread::thread-observed-internal-real-time-delta-sec thr)) While the current sources still have: ❯ grep -A 2 -B 2 '(tv-sec' crossbuild-runner/backends/arm/stuff-groveled-from-headers.lisp (define-alien-type nil (struct timeval (tv-sec (signed 32)) (tv-usec (signed 32)))) (define-alien-type nil (struct timespec (tv-sec (signed 32)) (tv-nsec (signed 32)))) I’m guessing that this is no longer the case on armhf anymore. I’m trying to test this on the porter box abel.debian.org. Best regards, Peter