Detect MCP server connection failures in Copilot debug logs

[Copilot]

The Copilot log parser was not detecting MCP server connection failures, allowing workflows to continue running with unavailable tools instead of failing fast with actionable error messages.

Changes

• Modified parseDebugLogFormat(): Scans debug logs for MCP connection errors using pattern [ERROR] Failed to start MCP client for remote server <name>: TypeError: fetch failed, extracts server names, and immediately calls core.setFailed() to fail the step when failures are detected

• Updated parseCopilotLog(): Propagates MCP failures from debug log parsing into result object for consistency

• Added test coverage: 5 test cases covering single/multiple failures, successful connections, deduplication, and verification that core.setFailed() is called with the correct error message

Behavior

// Debug log contains:
// [ERROR] Failed to start MCP client for remote server github: TypeError: fetch failed

// parseDebugLogFormat immediately calls:
core.setFailed("MCP server(s) failed to launch: github")

// Also returns:
result.mcpFailures = ['github']

Without MCP failures, mcpFailures is undefined and execution continues normally. The step fails immediately during log parsing rather than later in the bootstrap layer, providing faster feedback about MCP connection issues.

Original prompt

Update the copilot parser log javascript handler to detect when MCP server fail to connect. The error messages look like this:

2026-01-11T07:21:35.050Z [ERROR] Failed to start MCP client for remote server <server-name>: TypeError: fetch failed

When detecting these errors, fail the step.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[pelikhan]

@copilot when you detect a mcp failure, you should fail the step in parseDebugLogFormat

[Copilot]

@copilot when you detect a mcp failure, you should fail the step in parseDebugLogFormat

Done. Now calling core.setFailed() immediately in parseDebugLogFormat when MCP connection failures are detected. Updated tests verify the call is made with the correct error message. (151e8bf)

[github-actions]

💀 Blimey! Changeset Generator failed and walked the plank! No treasure today, matey! ☠️

[github-actions]

🎬 THE END — Smoke Claude MISSION: ACCOMPLISHED! The hero saves the day! ✨

[github-actions]

✨ The prophecy is fulfilled... Smoke Codex has completed its mystical journey. The stars align. 🌟

[github-actions]

📰 VERDICT: Smoke Copilot has concluded. All systems operational. This is a developing story. 🎤

[github-actions]

Smoke Test Results (Claude)

Last 2 merged PRs:

• Add workflow: githubnext/agentics/weekly-research #8: Add workflow: githubnext/agentics/weekly-research
• Remove ai-inference, opencode, genaiscript agentic engines for now #10: Remove ai-inference, opencode, genaiscript agentic engines for now

Test Results:

• ✅ GitHub MCP: Retrieved PRs successfully
• ❌ Serena Go: Tool not available in environment
• ✅ Playwright: Navigated to GitHub, title verified
• ❌ Safe Input gh: Tool not available in environment
• ✅ File Writing: Created test file successfully
• ✅ Bash Tool: File verification successful

Overall Status: PARTIAL PASS (4/6 tests passed)

AI generated by Smoke Claude