I am building a new pipeline that needs to check GitHub pull requests. I had this portion working running with jtarchie/github-pullrequest-resource, but after switching to this pr resource, I am experiencing the following failure in the resource:

resource script '/opt/resource/check []' failed: exit status 1

stderr:
2019/01/03 02:03:13 failed to unmarshal request: json: unknown field "ref"

Running fly check-resource produces basically the same output.

I don't have any usual configuration at all, so I expected this to just work (after changing repo to repository). Here's my configuration for the resource:

resource_types:
- name: pull-request
  type: docker-image
  source:
    repository: teliaoss/github-pr-resource

resources:
- name: cli
  type: pull-request
  check_every: 1m
  source:
    repository: cloudfoundry/cli
    access_token: ((github-access-token))
    ignore_paths:
    - README.md
    - .github/

The access token gets interpolated correctly, and has the following scopes: repo/repo:status and repo/public_repo. The repository itself is public.

Any help would be appreciated. It seems to me that the check script is getting JSON back with an unexpected key, and I'm not sure how to address that. Has anyone seen this particular error message before?