clock related, intermittent failure in lease.TestPackage

[Anastasia]

From http://ci.jujucharms.com/job/github-merge-juju/975/ and more detailed http://ci.jujucharms.com/job/github-merge-juju/975/testReport/junit/github/com_juju_juju_worker_lease/TestPackage/:

----------------------------------------------------------------------
FAIL: manager_expire_test.go:194: ExpireSuite.TestClaim_ExpiryInFuture_TimePasses

manager_expire_test.go:219:
    fix.RunTest(c, func(manager *lease.Manager, clock *testclock.Clock) {
        // Ask for a minute, actually get 63s. Expire on time.
        err := getClaimer(c, manager).Claim("redis", "redis/0", time.Minute)
        c.Assert(err, jc.ErrorIsNil)
        clock.Advance(justAfterSeconds(newLeaseSecs))
    })
util_test.go:86:
    c.Fatalf("Store test took way too long")
... Error: Store test took way too long

[Joseph Phillips (manadart)]

This and its relatives below are stubborn heisenbugs.

- https://bugs.launchpad.net/juju/+bug/1631369
- https://bugs.launchpad.net/juju/+bug/1748381

I attempted to get at the latter of those. As noted in the report, there is a threshold of logging detail, that if passed makes failure unreproducible. I ran the test in a loop for a day.

[Joseph Phillips (manadart)]

And you are right. Something isn't playing ball in the clock implementation.

[John A Meinel (jameinel)]

Is running under '--race' useful at all? I'm just curious if the problem is
actually that we have a small race condition in the test. Though probably
it isn't a variable race as much as general concurrency issues. ('--race'
tells you if you're looking at a variable from 2 goroutines without
synchronization, but it won't tell you that you assume X changes before you
look at it, when actually it changes at a later time.)

On Thu, Aug 23, 2018 at 4:00 PM, Joseph Phillips <<email address hidden>
> wrote:

> And you are right. Something isn't playing ball in the clock
> implementation.
>
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[Anastasia (anastasia-macmood)]

I cannot reproduce this at all - we must have fixed it as part of other work.

I am marking this as Fix Released. Please open a different report if you are able to reproduce, attaching newer logs and possibly repro steps.