[aw-failures] [aw] Failure Investigator Report — 2026-08-11 (6h)

[github-actions]

Overview

Fix the Avenger workflow first — a deterministic Bun runtime segfault killed both of its runs in this window (8/8 execution attempts crashed), and it's the only P0 failure with zero existing tracking coverage. Everything else this cycle is a single-run, low-signal blip or a working-as-intended policy gate.

Fix roadmap

• P0 — Avenger Bun segfault: pin/bisect the Bun runtime and fast-fail the harness retry loop instead of burning 4 attempts on a confirmed crash. Tracked in the sub-issue below.
• P1: none identified this cycle.
• P2 — watch, don't ticket yet: Daily Assign Issue To User, Daily PR Code Quality Review, Daily AgentRx Trace Optimizer each had one unexplained/opaque failure — re-open this as P1 if any recur tomorrow. Daily Container Image Security Scan failed because it found real critical CVEs — that's the gate doing its job, not a bug, no action needed.

Failure clusters (severity-ranked) and evidence

Cluster	Severity	Workflow	Signature	Runs	Tracking
cluster-1	P0	Avenger	Bun/Claude Code CLI SIGSEGV, 100% of attempts	§31465993823, §31462571906	New gap → sub-issue
cluster-2	P2	Daily Assign Issue To User	Copilot CLI exits 1 after 3 retries, no root-cause line captured	§31463851158	Untracked, single occurrence
cluster-3	P2	Daily PR Code Quality Review	Tool-denial threshold hit reading own generated diff file (/tmp/gh-aw/agent/pr51948_go.diff)	§31463530917	Untracked — same failure class as #51547, different workflow/file; extend that issue's scope rather than duplicating
cluster-4	P2	Daily AgentRx Trace Optimizer	Job failed, truncated log shows only post-job cleanup — cause not visible in captured tail	§31462581875	Untracked, needs a full (untruncated) log pull if it recurs
cluster-5	P2	Daily Container Image Security Scan	Policy gate exits 1: "Critical vulnerabilities detected in container images"	§31462580227	Not a bug — scanner working as designed

Evidence — Avenger Bun segfault (cluster-1, P0):

• Both Avenger runs in the window (§31465993823 and §31462571906) crashed on every one of their 4 retry attempts with panic(main thread): Segmentation fault, signal=SIGSEGV — 8/8 attempts, 0 successes. Crash address is different each time (0x12, 0x21, 0x0, 0xFFFE000000000015), which is the signature of heap/GC corruption rather than a deterministic input-triggered bug. Bun's own panic message states: "This indicates a bug in Bun, not your code."
• audit-diff of the failed run against the nearest prior success (§31459752206) rules out a network/policy cause: the failed run successfully made 43 api.anthropic.com calls and 19 GitHub API calls before crashing, and there are no anomalous firewall/domain deltas. The crash happens after real, working API traffic — it's an in-process Bun runtime fault, not a sandbox or tool-permission issue.
• Secondary harness bug found in §31462571906: attempt 2's --continue retry failed with "no deferred tool marker" and the harness responded by permanently disabling --continue (failure_reason=harness_retry_path_invalid), forcing full fresh-context restarts for attempts 3 and 4 — which then also segfaulted. This wastes ~90s of runtime per failed run and loses conversation context on every retry.

Existing issue correlation:

• §51789 — "Fix Copilot CLI harness segfault (exit 139) killing Agent Performance Analyzer" does not cover cluster-1: that issue is a Copilot CLI crash in a different workflow. Cluster-1 is a Bun/Claude Code CLI crash in Avenger. Don't conflate them, but consider whether both point at a shared "harness segfault handling" gap worth a follow-up once both are root-caused.
• §51547 — "Step Name Alignment sandbox blocks its own input file" is the closest analog to cluster-3 (sandbox blocking a workflow's own generated file) — flagging for scope review rather than opening a duplicate.
• No open agentic-workflows issue was found to be fixed or stale based on this cycle's evidence — none closed.

Sub-issues created

• #aw_bunsegv — [P0] Fix Bun runtime segfault crashing Claude Code CLI in Avenger

References:

• §31465993823
• §31462571906
• §31459752206

Generated by 🔍 [aw] Failure Investigator (6h) · agent · 123.6 AIC · ⌖ 41.5 AIC · ⊞ 5.3K · ◷

• expires on Aug 17, 2026, 11:20 PM UTC-08:00

[github-actions]

This issue was automatically closed because it expired on 2026-08-18T07:20:46.280Z.

Closed by Workflow