X lock files are created which prevents Xwayland from starting

[bbb651]

I'm using cosmic-greeter with greetd with a niri session, and xwayland-satellite for Xwayland support.
Since updating my (archlinux) system, specifically:

cosmic-greeter 1.0.0.alpha.5-1
cosmic-comp 1.0.0.alpha.5-1
niri 25.01-1
greetd 0.10.3-1
xwayland-satellite 0.5-2

The following files are created when logging in:

~$ ll -a /tmp | grep \\.X
-rw-r--r--  1 cosmic-greeter cosmic-greeter   11 Jan 16 19:15 .X0-lock
drwxrwxrwt  2 root           root             60 Jan 16 19:15 .X11-unix
drwxrwxrwt  2 root           root             40 Jan 16 19:15 .XIM-unix

Which prevent Xwayland (both rootful and rootless, including xwayland-satellite) from launching as display 0 (the default):

~$ Xwayland
(EE)
Fatal server error:
(EE) Could not create server lock file: /tmp/.X0-lock
(EE)

After removing /tmp/.X0-lock:

~$ Xwayland
_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
_XSERVTransMakeAllCOTSServerListeners: server already running
(EE)
Fatal server error:
(EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE)

After removing /tmp/.X0-unix it finally launches.

The lock files are created again when Xwayland starts but are owned by my user instead of cosmic-greeter (.XIM-unix isn't recreated if I remove it):

~$ ll -a /tmp | grep \\.X
-r--r--r--  1 bbb651 bbb651   11 Jan 16 22:04 .X0-lock
drwxrwxrwt  2 bbb651 bbb651   60 Jan 16 22:04 .X11-unix
drwxrwxrwt  2 root   root     40 Jan 16 19:15 .XIM-unix

Session files:

/usr/share/wayland-sessions/niri.desktop

[Desktop Entry]
Name=Niri
Comment=A scrollable-tiling Wayland compositor
Exec=niri-session
Type=Application
DesktopNames=niri

/usr/bin/niri-session

#!/bin/sh

if [ -n "$SHELL" ] &&
   grep -q "$SHELL" /etc/shells &&
   ! (echo "$SHELL" | grep -q "false") &&
   ! (echo "$SHELL" | grep -q "nologin"); then
  if [ "$1" != '-l' ]; then
    exec bash -c "exec -l '$SHELL' -c '$0 -l $*'"
  else
    shift
  fi
fi

# Try to detect the service manager that is being used
if hash systemctl &> /dev/null; then
    # Make sure there's no already running session.
    if systemctl --user -q is-active niri.service; then
      echo 'A niri session is already running.'
      exit 1
    fi

    # Reset failed state of all user units.
    systemctl --user reset-failed

    # Import the login manager environment.
    systemctl --user import-environment

    # DBus activation environment is independent from systemd. While most of
    # dbus-activated services are already using `SystemdService` directive, some
    # still don't and thus we should set the dbus environment with a separate
    # command.
    if hash dbus-update-activation-environment 2>/dev/null; then
        dbus-update-activation-environment --all
    fi

    # Start niri and wait for it to terminate.
    systemctl --user --wait start niri.service

    # Force stop of graphical-session.target.
    systemctl --user start --job-mode=replace-irreversibly niri-shutdown.target

    # Unset environment that we've set.
    systemctl --user unset-environment WAYLAND_DISPLAY XDG_SESSION_TYPE XDG_CURRENT_DESKTOP NIRI_SOCKET
elif hash dinitctl &> /dev/null; then
    # Check that the user dinit daemon is running
    if ! pgrep -u $(id -u) dinit &> /dev/null; then
      echo "dinit user daemon is not running."
      exit 1
    fi

    # Make sure there's no already running session.
    if dinitctl --user is-started niri &> /dev/null; then
      echo 'A niri session is already running.'
      exit 1
    fi

    # Start niri
    dinitctl --user start niri
else
    echo "No systemd or dinit detected, please use niri --session instead."
fi