auto cancellation of github PR tasks does not work well if initial task fails

[bhearsum]

Over in mozilla-releng/k8s-autoscale#160 I'm iterating on adding Taskgraph to that repo. Some of my early attempts failed to run a decision task correctly. Each push I made after such an attempt ended up with an error like:

Uh oh! Looks like an error! Details

Taskcluster-GitHub attempted to cancel previously created task groups with following scopes:

assume:repo:github.com/mozilla-releng/k8s-autoscale:*, queue:seal-task-group:taskcluster-github/*, queue:cancel-task-group:taskcluster-github/*

No task-group with taskGroupId: FKRVQdp5RcKNeGSYXeTNOw

---

• method: sealTaskGroup
• errorCode: ResourceNotFound
• statusCode: 404
• time: 2024-04-23T19:57:23.585Z

...and indeed, the group doesn't exist because the decision task failed.

Presumably we should catch and ignore 404s in this case?

[lotas]

Good point! Thanks for raising this.

Queue methods are returning 404 because task group didn't have a chance to be created yet, but github handler should detect this and silently ignore this

sending a fix here: #6989

[bhearsum]

Thanks for the quick fix!