Three coupled operator-reported pains from the 2026-05-31 download
event audit:
1. `[patreon][warning] Not allowed to view post N` was bubbling up as
an error event, bumping consecutive_failures and parking the source
in "needs attention." The classifier's tier-gated branch was gated
on `return_code in (1, 4)`. Gallery-dl returns a different exit
code for mixed-failure runs (e.g. paywall warnings + a missing
yt-dlp dep flipping the exit bits), so the branch never fired and
the path fell through to UNKNOWN_ERROR. Widen the gate: when no
source-level error fired AND tier-gated warnings are present,
classify as TIER_LIMITED regardless of return code.
2. Knuxy event #38275 (2026-05-31) ran 30 min and finalized with
"stranded by recovery sweep (no terminal status after time_limit)"
+ empty stdout/stderr. Root cause: subprocess.run timeout (900s)
and Celery soft_time_limit (900s) raced; when Celery won, SIGKILL
wiped the in-memory captured output and the DownloadEvent ended up
empty-logged 18 minutes later when the sweep finalized it. Drop
gallery-dl's default subprocess timeout to 870s — a 30s margin
shy of Celery's soft limit — so subprocess.TimeoutExpired always
wins the race and captures the partial stdout/stderr via the
existing handler.
3. `[downloader.ytdl][error] Cannot import yt-dlp or youtube-dl` was
firing on every video attachment, causing per-item download
failures that masked legitimate tier-gated classification.
Add yt-dlp>=2025.1 to requirements.txt. Once it's in the image,
video posts download normally and the per-item failure noise
disappears.
Tests added:
- pure tier-gated stderr with exit code 128 → TIER_LIMITED + success
- mixed tier-gated + yt-dlp + per-item failures → still TIER_LIMITED