Repository navigation
[aw-failures] Failure Investigation Report — 2026-04-21 (6h window) #27469
Description
Executive Summary
Two Design Decision Gate (claude engine) failures were detected in the 2026-04-21 investigation window. Both share an identical root cause: the workflow's 5-turn max-turns budget is insufficient for the ADR generation path. 19 of 23 runs in the window succeeded; the failures are isolated to this one workflow/root-cause combination.
Closed stale issue #27405 (expired, different root cause — MCP connection drop).
Failure Clusters
| Cluster | Workflow | Engine | Count | Root Cause | Priority |
|---|---|---|---|---|---|
| DDG max-turns | Design Decision Gate | claude | 2 | max_turns=5 insufficient for ADR write+push path |
P1 |
Evidence
Failed Runs
| Run ID | Branch / PR | Turns Used | Terminal Reason | ADR Written? |
|---|---|---|---|---|
| §24698134887 | copilot/configure-agentic-engine-driver (PR #27453) |
5/5 | max_turns |
Locally written, never pushed |
| §24697778261 | copilot/add-support-agentic-engine-opencode (PR #27466) |
5/5 | max_turns |
Not written (cut off mid-turn) |
Comparator (success): §24697555895 — PR #27458, no ADR required → noop in 4 turns ✅
Turn-by-turn breakdown for run §24698134887
| Turn | Action | Result |
|---|---|---|
| 1 | Read adr-prefetch-summary.json + design-gate-config.yml |
186 additions → ADR required |
| 2 | Read pr.json + pr.diff |
Full diff across 9 files |
| 3 | Check existing ADRs | None found for PR #27453 |
| 4 | mkdir -p docs/adr |
Success |
| 5 (last) | Write docs/adr/27453-*.md |
File written locally (6,195 bytes) — no turn left for push |
| — | Hit max_turns | push_to_pull_request_branch + safeoutputs never called |
Turn-by-turn breakdown for run §24697778261
| Turn | Action | Result |
|---|---|---|
| 1 | Read adr-prefetch-summary.json + design-gate-config.yml |
520 additions → ADR required |
| 2 | Read pr.json + pr.diff |
24 files, 520+ additions |
| 3 | Read file list (extra data-gathering step) | Turn consumed before ADR write |
| 4 | mkdir -p docs/adr |
Success |
| 5 (last) | Write ADR initiated |
Hit max_turns before write completed |
Root Cause
The "ADR needed" execution path requires a minimum of 6 turns:
- Read prefetch summary + config
- Read PR metadata + diff
- Check existing ADRs
mkdir docs/adr- Write ADR file
- Push to PR branch + call safeoutputs
The workflow is configured with max_turns=5, making this path structurally impossible to complete.
Existing Issue Correlation
| Issue | Status | Action |
|---|---|---|
| #27405 — Design Decision Gate failed (MCP connection drop) | Closed ✅ | Expired (Apr 21 05:36 UTC) + different root cause |
| #27411 — Failure Investigator Issue Group | Open | Parent for new sub-issues |
Fix Roadmap
| Priority | Fix | Effort |
|---|---|---|
| P1 | Increase max-turns from 5 → 7 in DDG workflow |
Low |
| P1 (alt) | Move mkdir docs/adr to pre-agent shell step |
Low |
| P2 | Combine Write + push_to_pull_request_branch into a single tool call |
Medium |
Sub-Issues Created
- [aw-failures] Design Decision Gate: increase max-turns for ADR generation path #27470 — Design Decision Gate: increase max-turns for ADR generation path
References:
Activity