transport.onerror does not work

[uinstinct]

Describe the bug

I want to get the error via the stdiotransport instance's onerror method. I have used pipe for stderr. Still the output does not appear. Maybe I am doing something wrong.

To Reproduce

I made a simple MCP client to replicate this behavior. You can find it here
https://github.com/uinstinct/sample-mcp/blob/e99c8b5c83a761db92e307cef03d452719c74620/src/client.ts#L11-L13

1. clone the repo
2. npm run build
3. npm run client
4. see that the onerror console log is not printed

Expected behavior
Should output the error from the onerror method

Logs
If applicable, add logs to help explain your problem.

Additional context
Add any other context about the problem here.

[Areo-Joe]

client.connect() modifies the listener. If you want your listener to be called, set it after client.connect().

  const client = new Client({
    name: "example-client",
    version: "1.0.0",
  });

  await client.connect(transport);

  transport.onerror = (error) => {
    console.log("debug caught", error);
  };

[uinstinct]

client.connect() modifies the listener. If you want your listener to be called, set it after client.connect().

const client = new Client({
name: "example-client",
version: "1.0.0",
});

await client.connect(transport);

transport.onerror = (error) => {
console.log("debug caught", error);
};

This does not work 😕
Am only getting the response from my console logs

Edit: Is it possible you can help with a minimal example?

[shellRaining]

update to 1.13.3 can solve this

[uinstinct]

Thanks a ton!