add instructions for WSL2

[hubisan]

Will adapt README.org once WSL2 it for non-insiders as well
(Update 25.09.2020: got access WSL2 on one computer, will have a go and try to get this working)

TODOs from everything in here so far:

• Add https://docs.microsoft.com/en-us/windows/wsl/install-win10 and adapt instructions.

• Have to go through the installation (or check a video or the ms documentation) with WSL and WSL2 to see if it does setup a user for you and sets it as default user. Adapt the documentation accordingly. Looks like it does - https://www.youtube.com/watch?v=RTATnSA47Ak

• Add the best way to connect to the DISPLAY for WSL2. There are multiple solutions in [WSL 2] WSL 2 cannot access windows service via localhost:port microsoft/WSL#4619:

  • The last comment Unable to accessing Windows applications from WSL microsoft/WSL#4793 (comment) looks promising and is fully documented at https://github.com/famelis/wsl2-x11. Hmm, got changed, has access control now disabled as well.

  • Another secure solution from Unable to accessing Windows applications from WSL microsoft/WSL#4793 (comment) and then https://github.com/cascadium/wsl-windows-toolbar-launcher#troubleshooting

  • Or the not so safe way (not quite sure about the consequences) by just disabling the access control in VcXsrv Unable to accessing Windows applications from WSL microsoft/WSL#4793 (comment) and then to set the display automatically use export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0. In the comment it is done manually.

  • This SOF answer tells you how to add a firewall rule. https://stackoverflow.com/a/61110604/1365754 The IP address is not working for me, probably have to use the one from resolv.conf.

  • This SOF answer use another approach for the IP (in comments) as resolv.conf can have muliple IPs it seems. export DISPLAY=$(ip route | awk '/default via / {print $3; exit}' 2>/dev/null):0

  • Already existing Windows Firewall Rules need to be checked. There might be one automatically created blocking VcXsrv.

• Add a troubleshooting section

  • The post touches a few problems that might occur. Could add problems and solutions to the FAQ or make a new section for it. Following problems and solutions are mentioned: blurry screen or blurred images, fragmented disk error.
  • The solution of the memory issue (WSL 2 consumes massive amounts of RAM and doesn't return it microsoft/WSL#4166) is critical.

• Add a troubleshooting section

  • The post touches a few problems that might occur. Could add problems and solutions to the FAQ or make a new section for it. Following problems and solutions are mentioned: blurry screen or blurred images, fragmented disk error.
  • The solution of the memory issue (WSL 2 consumes massive amounts of RAM and doesn't return it microsoft/WSL#4166) is critical.

• Update FAQ

  • Instructing how to move the storage in WSL2 to another disk (how to move the vhdx of wsl2 to other disk MicrosoftDocs/WSL#412) is very useful (for me).

Helpful links to set up up WSL2:

• https://docs.microsoft.com/en-us/windows/wsl/wsl2-install
• https://autoize.com/xfce4-desktop-environment-and-x-server-for-ubuntu-on-wsl-2/
• https://www.reddit.com/r/emacs/comments/er248t/installing_emacs_on_wsl2_with_windows_but_it_works/
• [WSL 2] WSL 2 cannot access windows service via localhost:port microsoft/WSL#4619
• https://docs.microsoft.com/en-us/windows/wsl/wsl2-ux-changes
• https://docs.microsoft.com/en-us/windows/wsl/wsl2-faq

[psmith1303]

I forgot where I found this solution for the IP address under WSL2, but it works for me.

#
# Set up the DISPLAY for emacs
#
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0
#
# Setup HOME for emacs
#
export HOME=/mnt/c/Users/psmith/
cd $HOME

That said, one also need to run the X server so it accepts non-local connections, and change Windows Defender firewall to. I did a gross 'hack' and just turned it off the Public firewall.

[hubisan]

Thanks for the input. Don't have the need and time to try WSL2 atm.

Here is a link to setup the firewall it seems to make it secure:
microsoft/WSL#4106 (comment)

[hubisan]

Another link that helps with WSL2 setup:
post on reddit > Installing emacs on WSL2 with Windows, but it works

To properly connect the access control in VcXsrv is diabled (option -ac) so you don't have to touch the firewall settings. As mentionned this is not super safe:

Let's download VcXsrv to provide the GUI, install it ; launch it and accept the default setup, upon reaching the extra settings, complete it with the last box ticked as well, like this. I know it's not super safe. This allows WSL2 to connect properly though, per this issue and this github.

Looks like WSL makes a user for you now the first time it is started and probably sets it as default user:

Once WSL is installed, I launch it and it prompts for a username and password, I oblige.

• TODO Have to go through the installation with WSL and WSL2 to see if it does setup a user for you and adapt the documentation accordingly.
• TODO The post touches a few problems that might occur. Could add them to the FAQ or make a new section for problems you might encounter and the solution for it. Following problems and solutions are mentioned: blurry screen or blurred images, fragmented disk error.

[Adriankhl]

I am trying to use emacs in WSL2. A few comments about this page:

1. Why do you recommend installing lxde desktop? You don't need a desktop environment to run emacs.

2. Instructing how to move the storage in WSL2 to another disk (how to move the vhdx of wsl2 to other disk MicrosoftDocs/WSL#412) is very useful (for me).

3. The solution of the memory issue (WSL 2 consumes massive amounts of RAM and doesn't return it microsoft/WSL#4166) is critical.

4. I realized that everyone is recommending vcxsrv, and almost no discussion about Cygwin/X which (I believe) the vcxsrv is based on. However, XWin could provide some advantages (https://github.com/mviereck/runx), note that the script there doesn't work for me. It is not hard to setup, just install Cygwin (I use scoop) and run the setup again to install xinit. Then run something like cygwin.exe -c "XWin :0 -listen tcp -retro -lesspointer -multiwindow -clipboard -ac -wgl"& to start the XWindows. At first glance, emacs feels equally smooth. Maybe a benchmark is useful to distinguish between the two.

[hubisan]

@Adriankhl Thanks for your inputs.

Will be adding instructions for cygwin/x and remove the desktop installation part (made two new issues).

Will be adding WSL2 instructions once it is available to non-insiders. Hopefully the memory leakage will be fix by then. If not I will be adding it.

[ianyepan]

I had some trouble setting up X server for WSL2. Now that I solved it, thought I might contribute to this thread.
So this is the reddit thread that helped me: microsoft/WSL#4106
The TL;DR is, set DISPLAY to include the IP address of the host, and don't forget to pass -ac flag/argument when launching Vcxsrv.

[lgrosz]

The stuff I had to do to get it working on WSL2 was

• Install vcxsrv, run with the -ac command
• Run export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0 on WSL2
• Run the "Incoming Connections" trouble shooter on Windows after trying to run something graphical on WSL2

That last bit was the last hurdle for me, and I can't believe a Windows trouble shooter worked for once.