process-attachments.sh exits 1 with no manifest on zero-attachment issue (spec says exit 0 + empty manifest) #186

Problem

Spec (idd-diagnose SKILL.md Step 1.5):
「0 — 下載完成(或 issue 無 attachment,empty manifest 已寫)」
「沒有 attachment → script 寫空 manifest 後 exit 0,Diagnosis Report 標明「issue 無 attachment」。」

實際行為（v2.84.0，2026-06-10，於 kiki830621/collaboration_su_ying_huang#26 diagnose 過程觀察）：

$ IDD_CALLER=idd-diagnose bash .../scripts/process-attachments.sh download 26
exit=1
# stdout/stderr 皆空
# .claude/.idd/attachments/issue-26/ 目錄建立但無 _manifest.json

Issue #26 body 無任何 attachment URL（GitHub release asset / user-attachments），預期走「無 attachment → 空 manifest + exit 0」路徑。

Type

bug

Expected

• exit 0
• .claude/.idd/attachments/issue-26/_manifest.json 寫入空 manifest
• caller（idd-diagnose）可直接在 report 標明「issue 無 attachment」

Actual

• exit 1（語意 = 「部分檔案下載失敗」，誤導 caller）
• 無 manifest 檔
• 無任何錯誤訊息（silent failure，違反「禁止靜默」原則）

Impact

idd-diagnose / idd-implement 的 attachment check 對零附件 issue 一律收到 false-negative exit code；下游「manifest 缺漏 → 警告重跑 diagnose」邏輯被誤觸發。

Current Status

Phase: closed
Last updated: 2026-06-10 by idd-close

Key Decisions

• 修 detect_urls() single point（三 call site 同修）；顯式 || return 2（$() 不繼承 errexit — fixture f5 抓到 set-e-based 修法會吞 gh 故障）
• 6-AI verify PASS（首次完整 ensemble 含 Codex）；Codex MEDIUM 經 DA 實證仲裁 reject
• process-attachments.sh exits 1 without writing empty manifest when issue has zero attachments (sister concern from PsychQuant/che-ical-mcp#154) #185 duplicate 併入（RCA 證據保留）；sisters: [test-infra] assert-helpers eval family re-expands literal $VAR in captured output under set -u — document + safe helper (sister from #186) #188（assert-helpers eval 陷阱）、[bug] process-attachments check/verify silently PASS on corrupt _manifest.json — verify is idd-close's gate (follow-up from #186) #189（corrupt manifest silent PASS）
• Complexity = Simple；Conflict Class = A_parallel_safe

Blocking

• (none)

Commits

• 989e117 fix: process-attachments zero-attachment silent death
• 3b3765f docs: exit-2 fetch-failure + test comment de-drift