can1357/oh-my-pi · error · Error

Adapter process exited before socket was ready

Error message

Adapter process exited before socket was ready

What it means

When launching a socket-based (stdio pipe or TCP) DAP adapter, the client waits for a readiness check (e.g. socket/port availability) before use. If the adapter process exits (non-null exitCode) before that check succeeds, this error is thrown because the process will never become ready. It distinguishes 'not ready yet' from 'adapter died at startup'.

Solutions

1. Run the adapter command manually with the same args/cwd to see its startup error output
2. Fix the adapter path, runtime, and launch configuration (program, cwd, env) in the resolved adapter config
3. Check the adapter's stderr/stdout logs for the crash reason; capture them at launch
4. Verify the adapter binary is executable and compatible with the platform (e.g. correct arch)

Example fix

// before
adapter: { command: 'node', args: ['--inspect', 'dbg.js'] } // crashes on old node
// after
adapter: { command: 'node', args: ['--loader', './dap-loader.mjs', 'dbg.js'] } // verify with: node --loader ./dap-loader.mjs dbg.js

const proc = Bun.spawn([adapter.command, ...adapter.args], { cwd, stderr: 'pipe' });
// surface early failure before waiting for readiness
proc.exited.then(code => { if (code !== 0) console.error(await new Response(proc.stderr).text()); });

try {
  await DapClient.connect({ adapter, cwd, timeoutMs: 10_000 });
} catch (err) {
  if (String((err as Error).message).includes('exited before')) {
    console.error('adapter startup failed; check adapter path/args and stderr logs');
  }
  throw err;
}

When it happens

Trigger: The adapter executable crashes immediately after launch (bad interpreter, missing module, invalid config passed via launch args); the launch command errors out before opening its socket; the adapter exits during the startup window while waitFor readiness is polling.

Common situations: Wrong adapter path or runtime in debug config (e.g. node version without required flags); a Python debugpy entrypoint typo'd so the process dies; adapter killed by missing environment variables or unresolvable cwd; port configured but adapter fails to bind and exits.

Related errors

• Adapter process exited before TCP port
• DAP adapter exited before write completed
• Socket not ready after
• DAP adapter is not running
• No active stack frame. Run stack_trace first or supply…

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/1e12f6a3f4876faf. Report an issue: GitHub.

Appendix: source

Thrown at packages/coding-agent/src/dap/client.ts:779

	try {
		return (await fs.stat(socketPath)).isSocket();
	} catch (error) {
		if (isEnoent(error)) return false;
		throw error;
	}
}

/** Poll a condition until it returns true, or timeout/process exit. */
async function waitForCondition(
	check: () => boolean | Promise<boolean>,
	timeoutMs: number,
	proc: { exitCode: number | null },
): Promise<void> {
	const deadline = Date.now() + timeoutMs;
	while (Date.now() < deadline) {
		if (await check()) return;
		if (proc.exitCode !== null) {
			throw new Error("Adapter process exited before socket was ready");
		}
		await Bun.sleep(50);
	}
	throw new Error(`Socket not ready after ${timeoutMs}ms`);
}

/** Connect once to a TCP DAP server. */
async function connectTcpSocket(host: string, port: number, onClose?: () => void): Promise<SocketTransport> {
	const { promise, resolve, reject } = Promise.withResolvers<SocketTransport>();
	let streamController: ReadableStreamDefaultController<Uint8Array>;
	let opened = false;
	const readable = new ReadableStream<Uint8Array>({
		start(controller) {
			streamController = controller;
		},
	});

	void Bun.connect({

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