set-issue-field safe-output: 'No issue fields were discovered for this repository' #33847

Bug report

Describe the bug

The built-in set-issue-field safe-output silently skips all field updates with the message:

No issue fields were discovered for this repository. Verify issue fields are enabled and visible to this token.

The repository has issue fields configured and accessible via the GraphQL API (issueFields connection returns results). The agent correctly calls set_issue_field with valid field names and values, but the safe-outputs handler in the safe_outputs job step fails to discover them.

Steps to reproduce

1. Configure a workflow with set-issue-field: max: 4 in safe-outputs
2. Repository has issue fields enabled (e.g. Priority, Visibility, Impact, Effort)
3. Permissions set to read-all (write permissions are rejected by strict mode)
4. Agent calls set_issue_field with valid payloads during execution
5. Safe-outputs processing step skips all calls

Observed behavior

From the workflow run logs:

safe_outputs | Process Safe Outputs | ⏭ Message 2 (set_issue_field) skipped — No issue fields were discovered for this repository. Verify issue fields are enabled and visible to this token.
safe_outputs | Process Safe Outputs | ⏭ Message 3 (set_issue_field) skipped — No issue fields were discovered for this repository. Verify issue fields are enabled and visible to this token.
safe_outputs | Process Safe Outputs | ⏭ Message 4 (set_issue_field) skipped — No issue fields were discovered for this repository. Verify issue fields are enabled and visible to this token.
safe_outputs | Process Safe Outputs | ⏭ Message 5 (set_issue_field) skipped — No issue fields were discovered for this repository. Verify issue fields are enabled and visible to this token.

The agent's MCP calls were valid:

{"field_name":"Priority","issue_number":"174","value":"P2"}
{"field_name":"Visibility","issue_number":"174","value":"High"}
{"field_name":"Impact","issue_number":"174","value":"Low"}
{"field_name":"Effort","issue_number":"174","value":"Low"}

Expected behavior

The safe-outputs handler should discover the repository's issue fields and apply the values. The fields are confirmed accessible via GraphQL:

{ repository(owner:"github", name:"plan-track-agentic-toolkit") {
  issueFields(first:20) { nodes { ... on IssueFieldSingleSelect { name options { name } } } }
}}

Returns: Priority (P0-P4), Visibility (High/Medium/Low), Impact (High/Medium/Low), Effort (High/Medium/Low).

Environment

• gh-aw version: v0.74.8
• Repository: github/plan-track-agentic-toolkit
• Workflow run: https://github.com/github/plan-track-agentic-toolkit/actions/runs/26245135458
• Permissions: read-all
• Toolsets: [issues, labels]

Workaround

Using a custom jobs safe-output that directly PATCHes the Issues REST API with the fields payload works correctly. Only the built-in set-issue-field handler fails to discover fields.