My suspect is systemd-timesyncd: See src/timesync/timesyncd-manager.c:
/* * Maximum delta in seconds which the system clock is gradually adjusted * (slewed) to approach the network time. Deltas larger that this are set by * letting the system time jump. The kernel's limit for adjtime is 0.5s. */ #define NTP_MAX_ADJUST 0.4 I suspect the boost compilation's load made the internal clock diverge enough for systemd to jump the time. The default PollIntervalMaxSec is 2048 seconds in systemd. I can reduce it in systemd, but there is a jump as high as 0.85 in https://objectstorage.prodstack4-5.canonical.com/v1/AUTH_77e2ada1e7a84929a74ba3b87153c0ac/autopkgtest-focal/focal/amd64/b/boost1.71/20200317_211804_626ff@/log.gz which could not have been prevented by just halving the default. How about changing the autopkgtest setup to either change a default or disable systemd-timesyncd or install chrony instead? ** Also affects: systemd (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1880839 Title: Clock skew on testbeds To manage notifications about this bug go to: https://bugs.launchpad.net/auto-package-testing/+bug/1880839/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs