In #4700 while fixing a data race I made an incorrect assumption about
the return value of StateChangeConf, and ended up changing the behavior
in the timeout case to always return:
> timeout while waiting for state to become '[success]'
When it used to capture the "most recent error" from the function
itself.
It's much more useful to see that error bubbling up, so here we revert
to pulling it out of the function as we did before, and we protect
against the data race with a good old fashioned mutex.
The implementation was attempting to capture the error using a scoped
variable reference, but the error value is already exposed via the
return value of `WaitForState()`. Using that instead fixes the data
race.
Fixes the following data race:
```
==================
WARNING: DATA RACE
Read by goroutine 74:
github.com/hashicorp/terraform/helper/resource.Retry()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/wait.go:35 +0x284
github.com/hashicorp/terraform/helper/resource.TestRetry_timeout()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/wait_test.go:35 +0x60
testing.tRunner()
/private/var/folders/vd/7l9ys5k57l91x63sh28wl_kc0000gn/T/workdir/go/src/testing/testing.go:456 +0xdc
Previous write by goroutine 90:
github.com/hashicorp/terraform/helper/resource.Retry.func1()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/wait.go:20 +0x87
github.com/hashicorp/terraform/helper/resource.(*StateChangeConf).WaitForState.func1()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/state.go:83 +0x284
Goroutine 74 (running) created at:
testing.RunTests()
/private/var/folders/vd/7l9ys5k57l91x63sh28wl_kc0000gn/T/workdir/go/src/testing/testing.go:561 +0xaa3
testing.(*M).Run()
/private/var/folders/vd/7l9ys5k57l91x63sh28wl_kc0000gn/T/workdir/go/src/testing/testing.go:494 +0xe4
main.main()
github.com/hashicorp/terraform/helper/resource/_test/_testmain.go:84 +0x20f
Goroutine 90 (running) created at:
github.com/hashicorp/terraform/helper/resource.(*StateChangeConf).WaitForState()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/state.go:127 +0x283
github.com/hashicorp/terraform/helper/resource.Retry()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/wait.go:34 +0x276
github.com/hashicorp/terraform/helper/resource.TestRetry_timeout()
/Users/phinze/go/src/github.com/hashicorp/terraform/helper/resource/wait_test.go:35 +0x60
testing.tRunner()
/private/var/folders/vd/7l9ys5k57l91x63sh28wl_kc0000gn/T/workdir/go/src/testing/testing.go:456 +0xdc
==================
```