WSL version: 1.0.3.0: no longer able to use external X server with Windows 10 (20H2)

[yubrshen]

Version

WSL version: 1.0.3.0 
Kernel version: 5.15.79.1 
WSLg version: 1.0.47 
MSRDC version: 1.2.3575 
Direct3D version: 1.606.4 
DXCore version: 10.0.25131.1002-220531-1700.rs-onecore-base2-hyp 
Windows version: 10.0.19042.2486

WSL Version

• WSL 2
• WSL 1

Kernel Version

Linux version 4.4.0-19041-Microsoft ([email protected]) (gcc version 5.4.0 (GCC) ) #2311-Microsoft Tue Nov 08 17:09:00 PST 2022

Distro Version

Ubuntu Release: 22.04

Other Software

emacs 28.1 running in Ubuntu 22.04/WSL1

Repro Steps

1. Start X server vcXsrv
2. start emacs on a terminal of Ubuntu 22.04
3. emacs running in terminal mode, not using the X server running as before

Expected Behavior

The emacs should be started in GUI mode.

Actual Behavior

The emacs was started in terminal mode, not GUI one.

Diagnostic Logs

Some more observations.

1. My Windows version might be too old to take advantage of WSL2/WSLg to run the Linux GUI applications properly.
2. Indeed, Ubuntu 22.04 still runs in WSL 1 mode

I'd be happy to be able to use an external X server to run GUI emacs, but I cannot now. Even if I run vcXsrv, the X server would not be used by emacs GUI.
If I could revert back to the earlier version of WSL. I cannot find an earlier version of WSL to restore.

[yubrshen]

The problem is solved:
Inspired by https://github.com/hubisan/emacs-wsl/blob/master/run-emacs-wsl-1/wsl-1_2-emacs.bat
I changed to the following

export DISPLAY=:0.0

from
export DISPLAY=127.0.0.1:0.0

then I can start GUI app in Ubuntu/WSL1 again.