Looks like first there’s a 5s delay establishing the connection (normal), but also, screen is being used which is unexpected.

I think that’s the most likely culprit here as screen can spit out extra data or even re-render in some cases (doubt that’s what’s happening though).

Maybe we add a way to disable screen, even when it’s present. We could add backend support to the init payload, for example. Or maybe we can make the agent ignore screen in the test some other way. Thoughts/preference here @code-asher?

2023-12-12T12:29:54.1530623Z     t.go:84: 2023-12-12 12:29:43.234 [debu]  agent.reconnecting-pty: spawning screen client  remote=[fd7a:115c:a1e0:4d37:ab3e:19ab:e49b:c41]:33297  local=[fd7a:115c:a1e0:4bbe:9a01:8a64:2780:efac]:2  message_id=13a71e00-e630-47ac-85f7-094c6002e620  connection_id=1e1ceed0-3a78-464a-b646-90e2980671a8  screen_id=0c5e10fa
2023-12-12T12:29:54.1532423Z     t.go:84: 2023-12-12 12:29:43.456 [debu]  agent.reconnecting-pty: unable to read pty output; screen might have exited  remote=[fd7a:115c:a1e0:4d37:ab3e:19ab:e49b:c41]:33297  local=[fd7a:115c:a1e0:4bbe:9a01:8a64:2780:efac]:2  message_id=13a71e00-e630-47ac-85f7-094c6002e620  connection_id=1e1ceed0-3a78-464a-b646-90e2980671a8  error=EOF
2023-12-12T12:29:54.1534257Z     t.go:84: 2023-12-12 12:29:43.456 [debu]  agent.reconnecting-pty: killed process with error  remote=[fd7a:115c:a1e0:4d37:ab3e:19ab:e49b:c41]:33297  local=[fd7a:115c:a1e0:4bbe:9a01:8a64:2780:efac]:2  message_id=13a71e00-e630-47ac-85f7-094c6002e620  connection_id=1e1ceed0-3a78-464a-b646-90e2980671a8  error="os: process already finished"

It could be the startup message that appears in the bottom left corner that is causing the extra bytes.

My first draft actually did have a backend parameter, we could bring that back. But, it feels a bit wrong to me because really I think the other backend method should probably not exist given the bugs it has. Crazy it can input random characters and drop modes, among other issues. 😆

I think my preferences in order would be:

1. Adjust the test to account for the message (maybe we can allow either 5120 or 1024?)
2. See if we can eliminate the message (I am not sure there is a way)
3. Replace both backends with something else (something that does xterm-compatible terminal emulation)
4. Disable screen for the test

If we need to disable screen, even if temporarily, in the buffer backend tests we disable screen by setting PATH. But if that will not work here then a backend parameter seems like the way to go.