command/pr: No results or errors returned when cancelled due to "cannot find commit"

[bflad]

Version

v0.2.0 (patched with #28)

Description

While kicking off a few tests via tctest pr --wait and merging other things into VCS, ran into a situation where TeamCity cancelled a run with a temporary VCS error. This was however not surfaced back to the client running the testing in any form.

Opening the build:

Expected Behavior

$ tctest pr --wait 13430
Discovering tests for pr #13430 (https://github.com/terraform-providers/terraform-provider-aws/pull/13430)...
    TestAccAWSLightsailInstance
triggering refs/pull/13430/merge for (TestAccAWSLightsailInstance)...
  bflad@--OMITTED--#Aws_ProviderAwsAlternate
  build 114694 queued: https://--OMITTED--/viewQueued.html?itemId=114694
Waiting for build 114694 status to be 'finished'...
ERROR: Canceled (Error while applying patch; cannot find commit cbc11326b6340439ac52b1baa58f38e1d0ef62dd in the https://github.com/terraform-providers/terraform-provider-aws repository, possible reason: refs/pull/13430/merge branch was updated and the commi...
$ 

Actual Behavior

$ tctest pr --wait 13430
Discovering tests for pr #13430 (https://github.com/terraform-providers/terraform-provider-aws/pull/13430)...
    TestAccAWSLightsailInstance
triggering refs/pull/13430/merge for (TestAccAWSLightsailInstance)...
  bflad@--OMITTED--#Aws_ProviderAwsAlternate
  build 114694 queued: https://--OMITTED--/viewQueued.html?itemId=114694
Waiting for build 114694 status to be 'finished'...
$ 

(No errors or results)