spacedriveapp/spacedrive · error · anyhow::Error

Failed to write chunk data: {}

Error message

Failed to write chunk data: {}

What it means

The serialized chunk payload (rmp-encoded chunk message) could not be written to the send stream. Same failure class as the length-prefix write, but failing mid-payload indicates an abrupt reset (stream or connection error) rather than a between-chunks disconnect. The transfer aborts at the current chunk.

Source

Thrown at core/src/ops/files/copy/strategy.rs:1221

			crate::service::network::protocol::file_transfer::FileTransferMessage::FileChunk {
				transfer_id,
				chunk_index,
				data: encrypted_data,
				nonce,
				chunk_checksum: *chunk_checksum.as_bytes(),
			};

		let message_data = rmp_serde::to_vec(&chunk_message)?;

		send_stream.write_u8(0).await?;
		send_stream
			.write_all(&(message_data.len() as u32).to_be_bytes())
			.await
			.map_err(|e| anyhow::anyhow!("Failed to write message length: {}", e))?;
		send_stream
			.write_all(&message_data)
			.await
			.map_err(|e| anyhow::anyhow!("Failed to write chunk data: {}", e))?;
		send_stream
			.flush()
			.await
			.map_err(|e| anyhow::anyhow!("Failed to flush stream: {}", e))?;

		file_transfer_protocol.record_chunk_received(
			&transfer_id,
			chunk_index,
			bytes_read as u64,
		)?;

		bytes_transferred += bytes_read as u64;
		if let Some(callback) = progress_callback {
			callback(bytes_transferred, total_size);
		}

		chunk_index += 1;

View on GitHub (pinned to 6dfeccf211)

Solutions

1. Retry the copy job from its recorded chunk state
2. Inspect peer logs for why the receive side stopped (disk full, panic, restart)
3. On slow links, verify keep-alive and idle settings suffice for the transfer duration
4. Rule out middleboxes interfering with long-lived UDP flows

// A mid-payload reset kills the whole stream; rerun the transfer from its chunk state.
if let Err(ref e) = stream_file_data(/* ... */).await {
    if e.to_string().contains("chunk data") {
        tracing::warn!(error = %e, "stream reset mid-chunk, retrying transfer");
        tokio::time::sleep(std::time::Duration::from_secs(2)).await;
        return stream_file_data(/* ... */).await;
    }
    return Err(e.clone());
}

When it happens

Trigger: Peer resets the stream while the payload write is in flight; connection-level error (timeout, path change) surfacing during a large write; send buffer invalidated by connection close.

Common situations: Peer application closed the stream abruptly, QUIC idle timeout exceeded on slow links, abrupt network transitions such as Wi-Fi to cellular.

Related errors

• Failed to write message length: {}
• Failed to flush stream: {}
• Failed to open stream: {}
• Failed to finish stream: {}
• Transfer error: {}

AI-assisted analysis of spacedriveapp/spacedrive@6dfeccf211 (2026-08-16). Data as JSON: /api/errors/b2c40c64bf686b67. Report an issue: GitHub.