chenhg5/cc-connect · error

acp: read closed: %w

Error message

acp: read closed: %w

What it means

Raised inside the transport readLoop when reading a line from the agent's stdout fails (including normal io.EOF at process exit). It is propagated to cancel all pending RPC calls; callers see their outstanding requests fail. EOF is expected at shutdown; non-EOF indicates the pipe broke or the process died unexpectedly.

Source

Thrown at agent/acp/rpc.go:74

		pending: make(map[string]chan rpcOutcome),
		onNotif: onNotif,
		onReq:   onReq,
	}
}

func (t *transport) readLoop(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			return
		default:
		}
		line, err := t.readLine()
		if err != nil {
			if err != io.EOF {
				slog.Debug("acp: read error", "error", err)
			}
			t.cancelAll(fmt.Errorf("acp: read closed: %w", err))
			return
		}
		if len(bytes.TrimSpace(line)) == 0 {
			continue
		}
		t.dispatchLine(line)
	}
}

func (t *transport) readLine() ([]byte, error) {
	line, err := t.in.ReadBytes('\n')
	if err != nil {
		return line, err
	}
	return bytes.TrimSuffix(line, []byte("\r")), nil
}

func (t *transport) dispatchLine(line []byte) {

View on GitHub (pinned to 4000b2338a)

Solutions

1. If the error is EOF after Close(), it is normal teardown and can be ignored
2. For non-EOF errors, check whether the agent process crashed — look for a preceding EventError with its stderr
3. Avoid issuing new RPC calls after this error; the transport is dead and must be re-spawned

When it happens

Trigger: Thrown at agent/acp/rpc.go:74 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/3bf57c95ddf53bc0. Report an issue: GitHub.