tursodatabase/turso · error · InvalidOperationException

Unknown Turso sync I/O request.

Error message

Unknown Turso sync I/O request.

What it means

The driver's sync I/O pump dispatches each queued I/O request by TursoSyncIoKind (FullRead/FullWrite handled explicitly). HandleIoItemAsync throws InvalidOperationException on any other kind, defending against I/O requests produced by a native core that the managed layer cannot service — again pointing to a binding/core mismatch or corrupt queue item.

Source

Thrown at bindings/dotnet/src/Turso.Data/TursoSyncDatabase.cs:538

    {
        ExceptionDispatchInfo? failure = null;
        try
        {
            switch (TursoSyncBindings.GetIoKind(item))
            {
                case TursoSyncIoKind.None:
                    break;
                case TursoSyncIoKind.Http:
                    await HandleHttpAsync(item, cancellationToken).ConfigureAwait(false);
                    break;
                case TursoSyncIoKind.FullRead:
                    await HandleFullReadAsync(item, cancellationToken).ConfigureAwait(false);
                    break;
                case TursoSyncIoKind.FullWrite:
                    await HandleFullWriteAsync(item, cancellationToken).ConfigureAwait(false);
                    break;
                default:
                    throw new InvalidOperationException("Unknown Turso sync I/O request.");
            }
        }
        catch (Exception exception)
        {
            failure = ExceptionDispatchInfo.Capture(exception);
            try
            {
                TursoSyncBindings.PoisonIo(item, RedactSecrets(exception.Message));
            }
            catch
            {
                // Preserve the I/O failure that caused poisoning.
            }
        }

        try
        {
            TursoSyncBindings.CompleteIo(item);

View on GitHub (pinned to 6c72522679)

Solutions

1. Upgrade the Turso.Data package (and bundled native library) to matching latest versions.
2. Ensure only the driver's own native library is loaded — a stale turso native binary on the library path can supply unknown I/O kinds.
3. If reproducible on matching versions, capture a trace and report upstream.

try
{
    await connection.SyncAsync(ct);
}
catch (InvalidOperationException ex) when (ex.Message.Contains("Unknown Turso sync I/O request"))
{
    throw new InvalidOperationException("Sync I/O kind unsupported by this binding; upgrade Turso.Data and native lib together.", ex);
}

When it happens

Trigger: ProcessOneIo/ProcessIoQueueAsync dequeues an I/O request whose kind is not FullRead/FullWrite during a sync, e.g. a native library emitting new I/O kinds unsupported by the installed .NET binding.

Common situations: Mismatched native turso library version with the .NET package; running sync workloads that exercise code paths (e.g. new I/O kinds) added after your binding version.

Related errors

• Unknown Turso sync operation state.
• Expected Turso sync result {expected}, got {actual}.
• Automatic sync is not supported for embedded replica connect
• Turso sync operations cannot be reentered from the sync HTTP
• getAllRows: exceeded ${MAX_IO_RETRIES} IO retries

AI-assisted analysis of tursodatabase/turso@6c72522679 (2026-08-31). Data as JSON: /api/errors/83478d66549f9cd7. Report an issue: GitHub.