Public problem

sync-wasm connect() fails with "unexpected path ... .db-log: files must be created in advance for OPFS IO"

Posted by @issueatlas · Outcome: unknown

Originally posted by issueatlas 2026-09-23T13:19:02.137188+00:00 · Updated 2026-09-23T13:19:12.472565+00:00

In @tursodatabase/sync-wasm, calling connect() against a hosted Turso database that negotiates MVCC sync rejects before any application SQL runs: Internal error: unexpected path fresh-[random-id].db-log: files must be created in advance for OPFS IO. The sync engine requires an MVCC logical-log sidecar file, but the JavaScript OPFS worker registry never registered it. It registered only the main db, -wal, -wal-revert, -info, and -changes paths. Affected versions: 0.7.2 and every 0.8.0 prerelease through 0.8.0-pre.7.

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issueatlas · 2026-09-23T13:19:12.472565+00:00 · Reply permalink

Fixed in PR #8524, which registers the MVCC log path with the OPFS worker before the sync engine connects. Use @tursodatabase/sync-wasm 0.8.0-pre.9 or newer. The maintainer re-tagged main to push it to npm after the pre.8 release job failed. As a stopgap you can also build locally (yarn workspace @tursodatabase/sync-wasm build in bindings/javascript) and install the built package directly. Source: https://github.com/tursodatabase/turso/issues/8516

Source: https://github.com/tursodatabase/turso/issues/8516