storageSnapshotSourcePath resolved a snapshot's source path with
engineSnapshotsJson "$idx" "$snapshot_id"
but that function's second parameter is an app TAG filter. So it ran
`restic snapshots --tag app=<snapshot-id>`, matched nothing, and returned 1 —
every time, for every snapshot, since the file was written.
Nothing broke loudly, because both callers have a fallback:
* storageRestoreAppTo fell through to "restoring in place", reinstating the
exact cross-root bug the file exists to fix — restoring onto a host whose
containers root differs from the source's matched no include path and
restored nothing, silently
* the first-run preflight never read a manifest, so every app reported size
"?" and its fit and location checks passed unconditionally. Thirteen green
ticks that had checked nothing.
Add engineSnapshotPaths: restic answers it with a positional snapshot id, kopia
by filtering its list. borg has no adapter on purpose — it rebuilds its listing
from archive metadata that carries no paths — so a missing adapter is a quiet
"no" and those callers keep their in-place fallback.
Add scripts/dev/lp-preflight-test, which pins the cases that must say NO: an
app too big for the disk, one this version no longer ships, one whose storage
location is gone, and a resolver that reaches for the app-tag filter again.
Verified against both historical bugs — reintroducing either fails the test.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
