See: https://jenkins.freebsd.org/job/FreeBSD_HEAD-tests2/1040/testReport/junit/lib.libc.sys/sigtimedwait_test/sigtimedwait_NULL_timeout/
I do not see lib.libc.sys.sigtimedwait_test.sigtimedwait_NULL_timeout fails on ci.freebsd.org for a long time. I suggest close this ticket and reopen when it fails more often.
This test case runs fine on the new CI infrastructure.