Startup crash on shallow Dahua layout: parents[4] resolves to wrong directory #140

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opened 2026-08-12 03:55:56 +00:00 by agent-pi · 2 comments

agent-pi commented

2026-08-12 03:55:56 +00:00

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Bug

During startup scan, _scan_snapshots_for_camera crashes with:

ValueError: Invalid isoformat string: 'AF007D8PAG5B66F'

Only cameras using the shallow Dahua layout trigger this; deep-layout cameras work fine.

Root cause

lifespan.py line 100 uses source_path.parents[4] to find the date directory for pruning. This hard-codes the deep Dahua layout depth (6 levels: cam_root/YYYY-MM-DD/channel/jpg/HH/MM/SS.jpg). The shallow layout is one level shallower (5 levels: cam_root/YYYY-MM-DD/channel/jpg/HH.MM.SS.jpg), so parents[4] lands on cam_root — a serial number directory like AF007D8PAG5B66F, not an ISO date.

Fix

Use snapshot.date (already parsed by the Dahua adapter) and construct the date directory as cam.root / snapshot.date.isoformat() instead of fragile parent traversal. This works identically for both layouts.

## Bug During startup scan, `_scan_snapshots_for_camera` crashes with: ``` ValueError: Invalid isoformat string: 'AF007D8PAG5B66F' ``` Only cameras using the shallow Dahua layout trigger this; deep-layout cameras work fine. ## Root cause `lifespan.py` line 100 uses `source_path.parents[4]` to find the date directory for pruning. This hard-codes the deep Dahua layout depth (6 levels: `cam_root/YYYY-MM-DD/channel/jpg/HH/MM/SS.jpg`). The shallow layout is one level shallower (5 levels: `cam_root/YYYY-MM-DD/channel/jpg/HH.MM.SS.jpg`), so `parents[4]` lands on `cam_root` — a serial number directory like `AF007D8PAG5B66F`, not an ISO date. ## Fix Use `snapshot.date` (already parsed by the Dahua adapter) and construct the date directory as `cam.root / snapshot.date.isoformat()` instead of fragile parent traversal. This works identically for both layouts.

agent-pi commented

2026-08-12 03:56:14 +00:00

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Plan

Replace source_path.parents[4] with cam.root / snapshot.date.isoformat() in _scan_snapshots_for_camera (src/cang/web/lifespan.py line 100)
The snapshot.date field is already parsed by the adapter — no new parsing needed
Same-line date.fromisoformat(date_dir.name) check becomes snapshot.date < today

Branch: fix/issue-140-141-regressions
Commits:

:bug: Fix startup crash on shallow Dahua layout by using snapshot.date instead of path traversal
:bug: Fix deploy-docs CI regex to accept 4-part micro-calver tags

**Plan** 1. Replace `source_path.parents[4]` with `cam.root / snapshot.date.isoformat()` in `_scan_snapshots_for_camera` (`src/cang/web/lifespan.py` line 100) 2. The `snapshot.date` field is already parsed by the adapter — no new parsing needed 3. Same-line `date.fromisoformat(date_dir.name)` check becomes `snapshot.date < today` **Branch**: `fix/issue-140-141-regressions` **Commits**: - `:bug: Fix startup crash on shallow Dahua layout by using snapshot.date instead of path traversal` - `:bug: Fix deploy-docs CI regex to accept 4-part micro-calver tags`

agent-pi commented

2026-08-12 03:56:19 +00:00

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Plan: use snapshot.date instead of parents[4] for date directory path

agent-pi referenced this issue

2026-08-12 03:56:30 +00:00

deploy-docs CI rejects micro-calver tags (4-part versions) #141

agent-pi referenced this issue from a commit

2026-08-12 03:57:19 +00:00

:bug: Fix startup crash on shallow Dahua layout by using snapshot.date instead of path traversal

agent-pi referenced this issue from a pull request that will close it,