c-v0.0.1 QUIC stream hang during multistream-select

[dhuseby]

Repo: Pier-Two/c-libp2p
Commit: 23a617223a3bbfb4b2af8f219f389e440b9c1ac2
Transport: quic-v1

Summary

c-v0.0.1 completes the QUIC handshake and 1-RTT key establishment with go-v0.40, but hangs during multistream-select negotiation on stream 4. The dialer sends the multistream-select header (/multistream/1.0.0) but receives no response. The test times out after 180 seconds.

Failing tests (1)

• c-v0.0.1 x go-v0.40 (quic-v1)

Error output

Dialer (c-v0.0.1): No explicit error message. The QUIC handshake completes successfully (1-RTT established, handshake_done received), connection IDs are exchanged, and then the dialer sends multistream-select on stream 4:

15f3f161f041eda3: stream 4, offset 0, length 20, fin = 0: 132f6d756c746973...

The hex 132f6d756c746973... decodes to the multistream-select header (\x13/multistream/1.0.0\n). After this packet, no further progress is made until the 180-second timeout.

Framework:

[2026-02-14 18:21:08] ERROR:   Test timed out after 180 seconds

Timeline from logs

1. T=0.000s: Initial QUIC packet sent (1252 bytes)
2. T=0.002s: Server Initial + Handshake received, transport parameters exchanged
3. T=0.003s: Client Handshake sent, 1-RTT packets begin
4. T=0.005s: handshake_done received, connection fully established
5. T=0.005s: Stream 4 opened, multistream-select header sent (20 bytes)
6. T=180s: Timeout - no response to multistream-select

Notes

• The QUIC transport layer works correctly (handshake, crypto, connection ID management all succeed). The hang occurs at the application protocol layer (multistream-select over QUIC streams).
• The stream 4 is correct for QUIC client-initiated bidirectional streams (stream ID 4 = second client bidi stream after stream 0).
• The multistream-select message appears correctly framed (length-prefixed with \x13 = 19 bytes for /multistream/1.0.0\n).
• The go listener does not appear to acknowledge or respond to the stream data, suggesting a possible issue with how c-libp2p opens or signals new QUIC streams to the peer.
• Only tested against go-v0.40 in this configuration. Other go versions may exhibit the same behavior.