No state data received from Terraform: No state data was…

Error message

No state data received from Terraform: No state data was received from Terraform. This is a bug and should be reported.

What it means

Returned by the proto6 gRPC provider wrapper (`grpcwrap/provider6.go`) during the streamed `WriteStateBytes` handling: after the streaming loop completes with no transport error, the total bytes received is zero, which is invalid because even an empty state serializes to non-zero bytes. The message explicitly says this is a Terraform-internal bug to be reported.

Solutions

Report the bug with the Terraform and provider versions and a reproduction (the message says so explicitly).
Try a different (stable) version of the provider, or of Terraform core, to bisect the regression.
If you maintain the provider, ensure your `WriteStateBytes` reads all chunks and accumulates non-empty bytes before responding.

Defensive patterns

Strategy: try-catch

Validate before calling

// Provider-side guard: refuse to close with zero bytes received.
if totalReceivedBytes == 0 {
    return errors.New("received zero state bytes from client; this is a Terraform core bug")
}

Try / catch

if _, err := srv.WriteStateBytes(...); err != nil {
    if strings.Contains(err.Error(), "No state data received from Terraform") {
        // report and bisect Terraform core vs provider versions
        log.Fatal("streaming-state protocol produced zero bytes; file a Terraform bug")
    }
    return err
}

Prevention

Pin stable Terraform core + provider versions together; avoid alphas for the streaming-state RPC.
If you maintain a provider, fully drain and validate the state byte stream before responding.
Capture core/provider versions in CI logs to make this reported bug reproducible.

When it happens

Trigger: The provider's `WriteStateBytes` gRPC handler receives a `SendAndClose` where the accumulated `state.Bytes()` length is 0 — the client (Terraform core) opened the byte stream but sent zero data chunks. This indicates a broken state serialization path in core or a misbehaving custom provider implementation of the streaming state API.

Common situations: Using an experimental/alpha provider that implements the streaming state migration API incorrectly; a Terraform core regression in the state-bytes sender; protocol mismatch between core and provider on the streaming-state RPC.

Related errors

AI-assisted analysis of hashicorp/terraform@d32a084675 (2026-08-11). Data as JSON: /api/errors/6f29d64eb54ce590. Report an issue: GitHub.

Appendix: source

Thrown at internal/grpcwrap/provider6.go:1107

		n, err := state.Write(chunk.Bytes)
		if err != nil {
			return fmt.Errorf("error writing state: %w", err)
		}
		totalReceivedBytes += n
	}

	if grpcErr != nil {
		return grpcErr
	}

	if int64(totalReceivedBytes) != expectedTotalLength {
		return fmt.Errorf("expected to receive state in %d bytes, actually received %d bytes", expectedTotalLength, totalReceivedBytes)
	}

	if totalReceivedBytes == 0 {
		// Even an empty state file has content; no bytes is not valid
		return errors.New("No state data received from Terraform: No state data was received from Terraform. This is a bug and should be reported.")
	}

	resp := p.provider.WriteStateBytes(providers.WriteStateBytesRequest{
		StateId:  stateId,
		TypeName: typeName,
		Bytes:    state.Bytes(),
	})

	err := srv.SendAndClose(&proto6.WriteStateBytes_Response{
		Diagnostics: convert.AppendProtoDiag([]*proto6.Diagnostic{}, resp.Diagnostics),
	})

	return err
}

func (p *provider6) LockState(ctx context.Context, req *tfplugin6.LockState_Request) (*tfplugin6.LockState_Response, error) {
	lockResp := p.provider.LockState(providers.LockStateRequest{
		TypeName:  req.TypeName,

View on GitHub (pinned to d32a084675)