GitHub Actions
GitHub Actions reusable workflow is missing workflow_call
For a workflow to be reusable, the values for `on` must include `workflow_call`.
GitHub Actions cannot treat a workflow as reusable unless the called workflow explicitly declares the workflow_call trigger.
Observed message
For a workflow to be reusable, the values for `on` must include `workflow_call`.
Why it happens
- A workflow is being called with jobs.<job_id>.uses but the target workflow does not declare workflow_call.
- A normal workflow file was copied and reused without adding the reusable workflow trigger.
- The target file was refactored and lost its workflow_call trigger.
How to fix it
- Add workflow_call under the on key in the called workflow.
- Keep standard event triggers and reusable workflow triggers separated clearly if the file needs both.
- Validate the called workflow after editing before updating callers.
