worker/lease manager_expire_test.go:206: ExpireSuite.TestClaim_ExpiryInFuture is flaky

Running under:
  go test -race -count=200 -failfast -test.timeout=20m -check.v

I got this test to fail:

FAIL: manager_expire_test.go:206: ExpireSuite.TestClaim_ExpiryInFuture

[LOG] 0:00.000 CRITICAL juju.clock timer 2073-03-03 02:00:00.000000005 -0840 -0840 not ready: 1h0m0s
[LOG] 0:00.000 TRACE lease_test [] next expire decided on 1h0m0s 2073-03-03 02:00:00.000000005 -0840 -0840
[LOG] 0:00.000 TRACE lease_test [] redis/0 asked for lease redis, no lease found, claiming for 1m0s
[LOG] 0:00.001 TRACE lease_test [] redis/0 claiming lease redis for 1m0s successful
[LOG] 0:00.001 TRACE lease_test [] ensuring we wake up before 1m0s at 2073-03-03 01:01:00.000000005 -0840 -0840
[LOG] 0:00.001 TRACE lease_test [] tick at 2073-03-03 01:01:03.000000004 -0840 -0840, running expiry checks
[LOG] 0:00.001 TRACE lease_test [] expire looking for leases to expire
[LOG] 0:00.001 WARNING lease_test [] reporting error to main loop: Store method called after test complete: Refresh []
[LOG] 0:00.001 TRACE lease_test [] exiting main loop with error: Store method called after test complete: Refresh []
fixture_test.go:131:
    c.Check(err, jc.ErrorIsNil)
... value *errors.Err = &errors.unformatter{message:"", cause:(*errors.Err)(0xc000328fa0), previous:(*errors.Err)(0xc0003292c0), file:"github.com/juju/juju/worker/lease/manager.go", line:167} ()
... error stack:
        github.com/juju/juju/worker/lease/util_test.go:149: Store method called after test complete: Refresh []
        github.com/juju/juju/worker/lease/manager.go:524:
        github.com/juju/juju/worker/lease/manager.go:183:
        github.com/juju/juju/worker/lease/manager.go:167:

In a successful run the log is supposed to look like:
PASS: manager_expire_test.go:27: ExpireSuite.SetUpTest 0.000s

[LOG] 0:00.000 CRITICAL juju.clock timer 2073-03-03 02:00:00.000000005 -0840 -0840 not ready: 1h0m0s
[LOG] 0:00.000 TRACE lease_test [] next expire decided on 1h0m0s 2073-03-03 02:00:00.000000005 -0840 -0840
[LOG] 0:00.000 TRACE lease_test [] redis/0 asked for lease redis, no lease found, claiming for 1m0s
[LOG] 0:00.000 TRACE lease_test [] redis/0 claiming lease redis for 1m0s successful
[LOG] 0:00.000 TRACE lease_test [] ensuring we wake up before 1m0s at 2073-03-03 01:01:00.000000005 -0840 -0840
[LOG] 0:00.000 TRACE lease_test [] tick at 2073-03-03 01:01:03.000000006 -0840 -0840, running expiry checks
[LOG] 0:00.000 TRACE lease_test [] expire looking for leases to expire
[LOG] 0:00.000 TRACE lease_test [] checking expiry on 1 leases
[LOG] 0:00.000 DEBUG lease_test [] expired 1 leases: redis
[LOG] 0:00.000 TRACE lease_test [] evaluating 0 blocks
[LOG] 0:00.001 TRACE lease_test [] next expire decided on 1h0m0s 2073-03-03 02:01:03.000000006 -0840 -0840
[LOG] 0:00.001 TRACE lease_test [] exiting main loop with error: catacomb 0xc0000e0a00 is dying
START: <autogenerated>:1: ExpireSuite.TearDownTest

It seems there is some sort of race with the Done() condition/Refresh is being called at an unexpected time.
Given that both of them do seem to be waking up at 01:01:03 and it is expecting to Refresh and then expire, it seems odd that it would sometimes claim that Refresh shouldn't be called.

Needs investigation.