Pipeline continues infinitely is python check script fails

[smarshie]

Summary

I have implemented a 'Hello World' pipeline and resource type. It appears that when the check script fails, the "preparing build" stage never completes.

Steps to reproduce

Given Concourse is running normally....

A) 1st attempt

1. Create and upload a pipeline whose only job has one step in its plan: to "get" a resource
2. Create and make available a "Hello World" docker image for the resource, containing check, in, out scripts which run against Python 3.9. The check script deliberately throws an Exception.
3. Run the pipeline

B) in step 2, Modify the check script so that it catches the exception and invokes sys.exit(1)
C) in step 2, Modify the check script so that it catches the exception and prints an empty array

[If I remove the line that throws the Exception everything works fine and the pipeline executes correctly. Likewise the check script works fine in each scenario when invoked using docker run]

Expected results

In all 3 cases I would expect the "preparing build" section to complete and show a failure, with stderr made available.

Actual results

"Preparing build" step continues indefinitely

Additional context

Triaging info

• Concourse version: v7.7.1
• Browser (if applicable):
• Did this used to work? No idea. I'm new to Concourse.

[taylorsilva]

Could you share some screenshots of the error and where you're seeing it in the UI?

If there are errors during a check you can see those errors by clicking on the resource from the pipeline overview page.
For example, for this pipeline: https://ci.concourse-ci.org/teams/examples/pipelines/git-triggered
you could see errors for the check on this page: https://ci.concourse-ci.org/teams/examples/pipelines/git-triggered