WLinux does not support "hot-launch" an XServer app (without explicitly specifying DISPLAY)

[n3rd4i]

Describe the bug One of the main features that WLinux is providing is:

Support for many Linux graphical applications with no need to configure display or libGL in Wlinux. (Requires a Windows-based X client, such as X410.)

The issue that I've found is that does not work in case of user wants to hot-launch an XServer app from e.g.:

1. cmd.exe
2. windows RUN (WIN + R)

To Reproduce Steps to reproduce the behavior:

1. Install x11-apps in Wlinux: sudo apt update && sudo apt install -y x11-apps
2. Run command (in cmd.exe): wlinux run DISPLAY=:0 xeyes
3. The xeyes window is now visible
4. Close the xeyes window
5. Run command (in cmd.exe): wlinux run xeyes
6. The xeyes window is NOT visible, error: Error: Can't open display:
7. Behaviour is identical in case of replacing wlinux run <xserver command> with wsl <xserver command> (assuming WLinux is default distro)

Expected behavior Based on the main features of WLinux expectation was that hot-launch is supported.

Basic Troubleshooting Checklist

[x] I have confirmed WSL is enabled: https://docs.microsoft.com/en-us/windows/wsl/troubleshooting#confirm-wsl-is-enabled. [x] I have searched Google for the error message. [x] I have searched the official Microsoft WSL issues page: https://github.com/Microsoft/WSL/issues. [x] I have searched the WLinux issues page: https://github.com/WhitewaterFoundry/WLinux/issues. [x] I have reset WLinux: Settings->Apps->Apps & features->WLinux->Advanced Options->Reset. [x] I have disabled and re-enabled WSL in Windows Features. [x] I have run Windows 10 updates and restarted.

What other troubleshooting have you attempted?

Insert here:

WLinux Version

Find: Settings->Apps->Apps & features->WLinux->Advanced Options->Version.

Insert here: 1.1.22.0

Windows Build

Run systeminfo | findstr /C:"OS" | clip in Command Prompt and insert here: OS Name: Microsoft Windows 10 Pro Insider Preview OS Version: 10.0.18252 N/A Build 18252 OS Manufacturer: Microsoft Corporation OS Configuration: Standalone Workstation OS Build Type: Multiprocessor Free

For help on retrieving: https://docs.microsoft.com/en-us/windows/wsl/troubleshooting#check-your-build-number

[sirredbeard]

Thank you for an excellent bug report. I will try to reproduce and report back.

[n3rd4i]

Just run this command ONLY at first launch of WLinux: echo export DISPLAY=:0 >> ~/.bashrc. This will append the command at last of .bashrc file. Also .zshrc for zsh.

The above allegedly workaround does not fix anything, problem persists after executing the proposed command.

[n3rd4i]

Check if this line export DISPLAY=:0 present at the end of .bashrc file in your WSL user home directory. If not then add that.

I can confirm that .bashrc contains export DISPLAY=:0 and behavior is as I already explained (issue not fixed). I guess that the file .bashrc is not even evaluated in case of "hot-launch" so it does not matter what this file contains.

[khuongduybui]

I'm using Fish shell and have X410 launched (if not already) and DISPLAY variable setting in my config.fish file. I also set my shell to /usr/bin/fish -l with chsh (I think the new setup script also asks to do this for you).

When I run wlinux run code from Win + R dialog, it does launch Visual Studio Code in x410.

[n3rd4i]

I also set my shell to /usr/bin/fish -l with chsh (I think the new setup script also asks to do this for you).

Indeed, using the above command parses the .bashrc file because the --login argument does that. (having export DISPLAY=:0 in .bashrc is not needed, it seems --login takes that from somewhere else)

So the question becomes how to change the /bin/bash to /bin/bash -l. Directly changing with chsh does not work (trying that break the shell).

chsh: Warning: /bin/bash -l does not exist

After this trying sudo su:

Cannot execute /bin/bash -l: No such file or directory

Luckily one could change it back to default with sudo vipw

I also tried this and it works as expected: wlinux run /bin/bash -lc xeyes

[khuongduybui]

Actually my bad. I don't have -l in my chsh either, just /usr/bin/fish. When I run wlinux run code, for example, it does load my config.fish without launching byobu (which is set to launch if status --is-login).

[n3rd4i]

So basically the only simple/supported way to hot-launch XServer based app is to install fish instead of bash and configure it.

@khuongduybui Maybe you could add a sample-partial configuration (config.fish) for such support? Or only export DISPLAY=:0 should exist @ the end of the file?

This could be a workable workaround even if breaks the original No need to configure DISPLAY quote from the docs

[PeteSL]

I added export DISPLAY=:0 to /etc/bash.bashrc before the interactive test and it now is set when I start WLinux from File Explorer on a directory but not when I use "wlinux run". A little closer...

[crramirez]

Please run this script in bash:

#!/bin/bash

#Copy configuration to  fish
sudo mkdir -p "${__fish_sysconf_dir:=/etc/fish/conf.d}"
echo "set -x DISPLAY :0" | sudo tee "${__fish_sysconf_dir}/display.fish"
# enable external libgl
echo "set -x LIBGL_ALWAYS_INDIRECT 1" | sudo tee -a "${__fish_sysconf_dir}/display.fish"
# speed up some GUI apps
echo "set -x NO_AT_BRIDGE 1" | sudo tee -a "${__fish_sysconf_dir}/display.fish"

And additionally you can now use Ctrl+V in fish

[PeteSL]

That's great if you want to run fish but I prefer bash since that is what most of my clients are running on their Linux systems. Origin of this thread is to get bash to work properly.

[crramirez]

Sorry man I didn't understand well the issue. Let me read it well. I tough that the problem was with fish. Probably the problem is with nologin shell which won't read the /etc/profile. I will make some tests

[crramirez]

Doesn't it work?

wlinux.exe run "bash -l -c xeyes" or wlinux.exe run "bash -l -c code" ?

Regards

[PeteSL]

wlinux.exe run xeyes or wlinux.exe run code does not have DISPLAY=:0. run wlinux run set to see that it is not set. Running your commands calling out the bash shell with the -l switch does set DISPLAY=:0 with my change to /etc/bash.bashrc Apparently, the "hot-launch" of the bash shell (default) does not execute /etc/bash.bashrc. So the question is, what does it execute so we can export DISPLAY=:0?

[crramirez]

This is because it executes a non-login shell. Read this with the explanation where to put the environment variables: https://unix.stackexchange.com/questions/38175/difference-between-login-shell-and-non-login-shell.

Here is a good explanation about this: https://stackoverflow.com/questions/902946/about-bash-profile-bashrc-and-where-should-alias-be-written-in

Regards

[PeteSL]

When a shell runs a script or a command passed on its command line, it's a non-interactive, non-login shell. Such shells run all the time: it's very common that when a program calls another program, it really runs a tiny script in a shell to invoke that other program. Some shells read a startup file in this case (bash runs the file indicated by the BASH_ENV variable

Where does BASH_ENV get set? /etc/profile already comes with export DISPLAY=:0 and, as I indicated, we can get the File Explorer shell start to set it via /etc/bash.bashrc. So it may be we can't set it automatically when simply running a command using the "run" command with wlinux, at least using the default bash shell?

[crramirez]

BASH_ENV is not set and setting it in an initialization files would cause the same issues as setting DISPLAY one

[sirredbeard]

I think one solution might be calling a bash script with wlinux.exe run script.sh that sets variables instead of a GUI app directly.

The other option might be to call the silently set DISPLAY using a shell call in the C++ launcher code on each launch here: https://github.com/WhitewaterFoundry/WLinux/blob/master/DistroLauncher/DistroLauncher.cpp#L117. But that would not be user configurable, would prevent users from forwarding X display to other servers. It would also have a slight impact on launch speed.

[n3rd4i]

since this is stalled, I will close.