timer_test subtests are not independent
Job #1773630 failed for 6d84bff5:
Only the first subtest failed below (timer_test.c:234 subthread_assert_true) but 2..5 reported failures.
1..5
# timer_test.c:234 subthread_assert_true
not ok 1 - ticker
# 0x22 != 0
# timer_test.c:144: error: Failure!
not ok 2 - once_life
# 0x22 != 0
# timer_test.c:144: error: Failure!
not ok 3 - once_idle
# 0x22 != 0
# timer_test.c:144: error: Failure!
not ok 4 - reset
# 0x22 != 0
# timer_test.c:144: error: Failure!
not ok 5 - purge
# 0x22 != 0
# timer_test.c:585: error: Failure!