cannot use WSLg and another X server *at the same time* with *different* DISPLAYs

[esumii]

Windows build number:

Microsoft Windows [Version 10.0.19045.2311]

Your Distribution version:

Debian 10.13

Your WSL versions:

>wsl --version
WSL バージョン: 1.0.3.0
カーネル バージョン: 5.15.79.1
WSLg バージョン: 1.0.47
MSRDC バージョン: 1.2.3575
Direct3D バージョン: 1.606.4
DXCore バージョン: 10.0.25131.1002-220531-1700.rs-onecore-base2-hyp
Windowsバージョン: 10.0.19045.2311

Steps to reproduce:

1. Start Ubuntu or Debian on WSL2
2. Start any X server proxy (such as https://github.com/nbdd0121/wsld , just for example) on a different DISPLAY such as :10 (not :0)

WSL logs:

pulseaudio.log
weston.log
stderr.log

WSL dumps:

None

Expected behavior:

The X server proxy should start with no error.

Actual behavior:

$ wsld
Failed to listen: Read-only file system (os error 30)
$ cat .wsld.toml
[x11]
display = 10
force = true
$ ls -al /tmp/.X11-unix/
total 12
drwxrwxrwx   2 root  root     60 Dec 13 15:23 .
drwxrwxrwt 189 root  root  12288 Dec 13 15:25 ..
srwxrwxrwx   1 sumii sumii     0 Dec 13 15:23 X0
$ touch /tmp/.X11-unix/X10
touch: cannot touch '/tmp/.X11-unix/X10': Read-only file system

This is because WSLg hijacks the entire directory /tmp/.X11-unix/ and does not allow to create a different socket like /tmp/.X11-unix/X10 .

A possible fix would be a symlink from only /tmp/.X11-unix/X0 to /mnt/wslg/.X11-unix/X0 instead of "hijacking" the entire directory.

[elsaco]

@esumii if you remount /tmp/.X11-unix with rw option then it works. This issue is being tracked by microsoft/WSL#9303

[esumii]

Thanks, but hijacking such a common directory is in general a bad idea. Symlink would be better.

sudo umount /tmp/.X11-unix
ln -sf /mnt/wslg/.X11-unix/X0 /tmp/.X11-unix/

[hideyukn88]

@esumii, we have previously implemented as symlink, but to support systemd, it settled the way it is, including make it read-only from non-system distro. The best solution for using non-WSLg X server, at this point, is to disable WSLg. But we keep looking for possible solution further, thanks!

[esumii]

Thanks but at least I need to use multiple X servers at the same time (for my class at the university, where students use various X servers).