Issue Labeler fails on most bug reports: 'needs-env-info' label does not exist

Start by reading utils/label_issues.py and .github/workflows/issue_labeler.yml, then reproduce the failure with a bug issue lacking “Diffusers version:” or inspect run 30841049166. Verify how VALID_LABELS and the per-label gh issue edit loop behave, and confirm that bug reports receive their intended labels without the job failing on needs-env-info.

Describe the bug

The Issue Labeler workflow fails on most new bug reports because it tries to apply a label that does not exist in this repository. It is 15 of the last 40 runs.

The error, from run 30841049166:

failed to update https://github.com/huggingface/diffusers/issues/14376: 'needs-env-info' not found
failed to update 1 issue
##[error]Process completed with exit code 1.

Cause

utils/label_issues.py appends needs-env-info to any issue it has labelled bug when the body does not contain a version string:

if "bug" in labels and "Diffusers version:" not in body:
    labels.append("needs-env-info")

needs-env-info is listed in VALID_LABELS, but there is no such label in the repository — gh label list has needs-code-example and no needs-env-info. .github/workflows/issue_labeler.yml then runs gh issue edit --add-label per label, and gh exits non-zero on the unknown one, failing the step.

Two consequences:

1. Every bug report without a pasted version string fails the labeler, which is exactly the population the label was meant to catch.
2. Because the labels are applied in a loop, a failure part-way can leave the earlier labels applied and the rest not, so an issue can end up partially labelled.

Suggested fix

The straightforward one is to create the needs-env-info label, since VALID_LABELS and needs-code-example both suggest it was intended to exist.

Independently of that, the apply step could avoid failing the whole job on one unknown label:

for label in $(...); do
  gh issue edit "$ISSUE_NUMBER" --add-label "$label" || echo "::warning::could not apply label: $label"
done

That keeps a missing or renamed label from silently costing an issue the rest of its labels in future.

I am happy to open a PR for the workflow change. Creating the label itself needs repository settings access, so that one has to be on your side.

Reproduction

Open any issue that the labeler classifies as a bug and that does not contain Diffusers version: in the body. #14376 is a recent example.

System Info

Not environment-specific; CI configuration. Observed on main at 6f2010e8b.

Who can help?

@DN6 — going by git log on utils/label_issues.py and .github/workflows/issue_labeler.yml.

Unrelated in cause but same area, in case it is useful to look at together: #14376 is a separate CI failure in the Secret Leaks workflow.