DATA RACE in holster/clock

[vtopc]

Version: v4.9.5

WARNING: DATA RACE
Write at 0x00c00006c0f8 by goroutine 16:
  github.com/mailgun/holster/v4/clock.(*frozenTime).unlockedStartTimer()
      github.com/mailgun/holster/v4/clock/frozen.go:151 +0x211
  github.com/mailgun/holster/v4/clock.(*frozenTime).startTimer()
      github.com/mailgun/holster/v4/clock/frozen.go:133 +0xa4
  github.com/mailgun/holster/v4/clock.(*frozenTime).AfterFunc()
      github.com/mailgun/holster/v4/clock/frozen.go:50 +0x1db
  github.com/mailgun/holster/v4/clock.(*frozenTime).NewTimer()
      github.com/mailgun/holster/v4/clock/frozen.go:[38](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:39) +0x38
  github.com/mailgun/holster/v4/clock.(*frozenTime).Sleep()
      github.com/mailgun/holster/v4/clock/frozen.go:30 +0x[39](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:40)
  github.com/mailgun/holster/v4/clock.Sleep()
      github.com/mailgun/holster/v4/clock/clock.go:76 +0x37
  github.com/mailgun/holster/v4/clock.(*FrozenSuite).TestSleep.func1()
      github.com/mailgun/holster/v4/clock/frozen_test.go:57 +0x3c
  github.com/mailgun/holster/v4/clock.(*FrozenSuite).TestSleep.func5()
      github.com/mailgun/holster/v4/clock/frozen_test.go:84 +0x47

Previous read at 0x00c00006c0f8 by goroutine 15:
  github.com/mailgun/holster/v4/clock.(*FrozenSuite).TestSleep()
      github.com/mailgun/holster/v4/clock/frozen_test.go:89 +0x63c
  runtime.call16()
      runtime/asm_amd64.s:724 +0x48
  reflect.Value.Call()
      reflect/value.go:368 +0xc7
  github.com/stretchr/testify/suite.Run.func1()
      github.com/stretchr/[email protected]/suite/suite.go:175 +0x6e6
  testing.tRunner()
      testing/testing.go:1[44](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:45)6 +0x216
  testing.(*T).Run.func1()
      testing/testing.go:1493 +0x47

Goroutine 16 (running) created at:
  github.com/mailgun/holster/v4/clock.(*FrozenSuite).TestSleep()
      github.com/mailgun/holster/v4/clock/frozen_test.go:84 +0x55d
  runtime.call16()
      runtime/asm_amd64.s:724 +0x48
  reflect.Value.Call()
      reflect/value.go:368 +0xc7
  github.com/stretchr/testify/suite.Run.func1()
      github.com/stretchr/[email protected]/suite/suite.go:175 +0x6e6
  testing.tRunner()
      testing/testing.go:14[46](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:47) +0x216
  testing.(*T).Run.func1()
      testing/testing.go:1493 +0x[47](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:48)

Goroutine 15 (running) created at:
  testing.(*T).Run()
      testing/testing.go:1[49](https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540#step:7:50)3 +0x75d
  github.com/stretchr/testify/suite.runTests()
      github.com/stretchr/[email protected]/suite/suite.go:220 +0x198
  github.com/stretchr/testify/suite.Run()
      github.com/stretchr/[email protected]/suite/suite.go:193 +0x9ae
  github.com/mailgun/holster/v4/clock.TestFrozenSuite()
      github.com/mailgun/holster/v4/clock/frozen_test.go:21 +0x44
  testing.tRunner()
      testing/testing.go:1446 +0x216
  testing.(*T).Run.func1()
      testing/testing.go:1493 +0x47
==================

https://github.com/mailgun/holster/actions/runs/3740540806/jobs/6349033540

---

one more proof

[vtopc]

The -tags holster_test_mode didn't help.