[P1] Smoke Copilot: send_slack_message handler not loaded — 10+ consecutive failures #20644

Problem

Smoke Copilot has been failing since 2026-03-11 ~13:10 UTC with a send_slack_message safe output handler error. This is a new regression — the workflow was healthy as of the Mar 11 07:29 health check.

Notably, the actual smoke tests are passing (11/11 applicable tests pass each run). The failure is at the safe-outputs processing level, not the agent level.

Error

⚠️ No handler loaded for message type 'send_slack_message' (message 7/7).
...
##[error]1 safe output(s) failed:
  - send_slack_message: No handler loaded for type 'send_slack_message'

Affected Runs

Root Cause

The Smoke Copilot workflow includes a send_slack_message safe output in its run, but the handler for this safe output type is not loaded/configured. This could be due to:

1. Missing Slack webhook secret (e.g., SLACK_WEBHOOK_URL not configured)
2. A recent code change removed or broke the send_slack_message handler registration
3. The safe-outputs section of smoke-copilot.md changed in a way that enabled Slack but the secret wasn't provisioned

Smoke Test Results (Still Passing!)

The actual smoke tests ARE working correctly — see issue #20624 for a sample run result showing 11/11 tests passing.

Impact

• Smoke Copilot workflow shows as "failure" in GitHub Actions (misleading)
• Copilot engine smoke testing appears broken but is actually running fine
• Slack notifications not being sent

Suggested Fix

1. Check smoke-copilot.md frontmatter for Slack configuration
2. Either configure the SLACK_WEBHOOK_URL secret or remove the send_slack_message safe output from the workflow
3. Check if recent changes to safe-outputs handler registration broke the Slack handler

References

• §22982121094 — Example failure run Fix firewall log parser rejecting invalid domains from Squid error messages #2330
• Relevant commits: 2026-03-11T18:07 "Fix safe_outputs: skip PR review comments outside PR context, register custom safe output handlers"
  Related to Workflow Health Manager - Meta-Orchestrator - Issue Group #19352

Generated by Workflow Health Manager - Meta-Orchestrator · ◷

• expires on Mar 13, 2026, 7:45 AM UTC