square/spincycle: job-runner/chain/traverser.go; 10 LoC

Found a possible issue in [square/spincycle](https://www.github.com/square/spincycle) at [job-runner/chain/traverser.go](https://github.com/square/spincycle/blob/4fa99714c120131a5bfc7985962fc35e1640cfb8/job-runner/chain/traverser.go#L632-L641)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first issue it finds, so please do not limit your consideration to the contents of the below message.

> range-loop variable jobId used in defer or goroutine at line 637

[Click here to see the code in its original context.](https://github.com/square/spincycle/blob/4fa99714c120131a5bfc7985962fc35e1640cfb8/job-runner/chain/traverser.go#L632-L641)

Click here to show the 10 line(s) of Go which triggered the analyzer.

```go
for jobId, activeRunner := range activeRunners {
wg.Add(1)
go func(runner runner.Runner) {
defer wg.Done()
if err := runner.Stop(); err != nil {
t.logger.Errorf("problem stopping job runner (job id = %s): %s", jobId, err)
hadError = true
}
}(activeRunner)
}

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: 4fa99714c120131a5bfc7985962fc35e1640cfb8

Open job-runner/chain/traverser.go around lines 632-641 at commit 4fa99714c120131a5bfc7985962fc35e1640cfb8. Read the surrounding shutdown path and inspect the reported range-loop capture in the goroutine. Compare the finding with the intended behavior, then classify it as Bug, Mitigated, or Desirable Behavior using the corresponding reaction.

Written by the indexing model from the issue text.