Bug: Terminal - Kitty socket invalid due to a launch race condition

[Fredzer]

Hey
I've run into a consistent issue with the Kitty terminal integration on desktop. The problem looks to be a race condition on the launch.

XPipe launches kitty --detach but attempts to use the communication socket with socat almost immediately.
Leaving not enough time for the socket to be created and causing socat to write a regular file instead, which breaks the connection.

This broken file then causes all subsequent launches (for simple shells or Zellij to fail with an Invalid listen_on

Errors parsing configuration
In final effective configuration:
Invalid listen_on=unix:/tmp/xpipe/fredzer/xpipe_kitty, ignoring
Press Enter or Esc to exit

$ ls -ld /tmp/xpipe/fredzer/xpipe_kitty 

Socket file

Invalid State -
-rw-r--r-- 1 /tmp/xpipe/fredzer/xpipe_kitty

Good State -
srwxr-xr-x 1 /tmp/xpipe/fredzer/xpipe_kitty

Environment:

• XPipe Version: 18.7/2025-09-17-05-52
• Operating System: EndeavourOS (Arch Linux)
• Hardware: Intel i9-10900K, NVMe Storage

Logs:
The logs show socat is called less than 200ms after kitty is launched, which triggers the race condition.
From the log + debug output steps- I've ran the commands manually (human speed) and kitty socket is created > open new kitty connection and connect just fine, so it does the job but its then tripping its self up.

Source Code:
This seems to be caused by the timing heuristic in KittyTerminalType.java

var elapsed = System.currentTimeMillis() - time;
// Good heuristic on how long to wait
ThreadHelper.sleep(5 * elapsed);

I've patched with timer wrappers for a while but wanted to raise it here as I haven't seen any similar issues logged.

[kovidgoyal]

You shouldnt need to use a heuristic here, java probably has some unix doman socket libraries you can use to check if the listening socket is accepting connections before running socat.

[crschnick]

@kovidgoyal So if I replace the heuristic, what is the best way to determine whether the kitty socat is fully started up?

If I do a while loop and run test -S <socket>, does that guarantee that once the socket exists, it will work properly?

Or do I also have to try to establish a connection to it to verify?

[kovidgoyal]

Not sure why you are using socat. Does java not have a proper socket
library? File existence is not sufficient. First of all, a UNIX socket
may not even be backed by a file, on Linux, for instance, there are
things called abstract namespace sockets. Not to mention that kitty can
listen on tcp sockets and file descriptors as well.

But more importantly, the socket file is created when bind() is called
but that does not guarantee that accept() has been called. The socket
will not accept connections till accept() has been called. The only sure
way is to try to connect to the socket and see if the connection
succeeds. This should be about five lines of code in java or really any
programming language. If for some reason you want to use socat only then
you call it in a loop till it succeeds.

[crschnick]

Alright, I will implement it like that then. There is unix socket support in Java, it just uses socat here as the usage of command-line tools is the gimmick of xpipe and that was the easiest option.

I will fix this in the next release by properly checking whether the socket accepts connections with Java calls.