lockfile descriptor persist through signal system

> I noticed that sometimes this happens: > > <img width="771" height="96" alt="Image" src="https://github.com/user-attachments/assets/050c997a-c5be-4f4a-8238-4d35a816b1f7" /> > > If I do the `yabai --stop-service` one is gone but the other remains > Even killing the process with `pkill yabai` doesn't do anything. > One process is listed forever. > I guess this is the reason both processes fight for lock. > > I also noticed that often times when I was connecting/disconnecting external monitor I saw additional yabai process (without icon) that disappeared after about 5 seconds > > <img width="765" height="108" alt="Image" src="https://github.com/user-attachments/assets/5510e389-476f-4e83-b703-09fc93892514" /> > > I rebooted my machine and in my script for `display_changed` event > ``` > yabai -m signal --add event=display_changed action="$HOME/.local/switch-flow/scripts/handle_display_changed.sh" & > ``` > note: this screenshot is taken after reboot so don't mind the PID being different from the other screenshot. > > I added `sleep 5` before `yabai -m query --windows id,app,title` > Now when I connect/disconnect the external monitor the "additional" yabai process doesn't show up. > Maybe this will give you some hints. > Perhaps too much was happening after display_changed event in my setup and that overwhelmed yabai. > It's quite possible that I haven't noticed this before because I started to use external monitor few weeks ago and that enforced some changes in my setup. _Originally posted by @kmiterror in [#2770](https://github.com/asmvik/yabai/issues/2770#issuecomment-4168801536)_