Oneshot canceled haylxon

A small bug in haylxoncaused screenshots to fail with this warning:

warning: oneshot canceled

But the tool still said:

info: Screenshots Taken and saved in directory hxnshots

No screenshot was actually saved.

What Was Happening

haylxon uses chromiumoxide to talk to Chrome. In the background, there’s a handler loop that keeps reading messages from Chrome and sending responses back through oneshot channels.

This was the code:

task::spawn(async move {
    while let Some(h) = handler.next().await {
        if h.is_err() {
            break;
        }
    }
});

It looks fine. If something errors, stop.

But Chrome sends non-fatal errors all the time — like console warnings from websites. When that happened:

1. handler.next() returned Some(Err(...))
2. The loop hit break
3. The handler stopped running
4. All pending oneshot senders were dropped
5. The receiver saw that and returned: "oneshot canceled"

So the screenshot call was waiting for a response… but the handler had already exited.

The connection wasn’t broken. We just stopped listening too early.

The Fix

I changed it to:

task::spawn(async move {
    while handler.next().await.is_some() {}
});

Now it keeps running until Chrome actually disconnects. It ignores non-fatal errors instead of shutting everything down.

That’s it.

One break statement was killing the whole message loop. Removing it fixed the issue completely.

Issue: #140