Require WSL 2

[awdeorio]

WSL 1 and Ubuntu 22.04 are incompatible. This is from @jamesjuett :

The intractable VS code debugging issue with "failed to set controlling terminal" is solved (sort of)! The problem manifests when students have WSL 1 rather than WSL 2. There's an incompatibility with newer versions of Ubuntu (I think - I'm assuming that's why we're starting to see it this term but haven't before). Some details here: microsoft/WSL#8356

The fix is to upgrade to WSL 2. There are two ways to do this.

• Their Windows version must be new enough. Windows 11 or Windows 10 Build 19041 or newer.
• Need to have virtualization enabled. Might need to do this in BIOS. (Although I see that less and less these days.)
• Need to have Windows Virtual Machine Platform enabled.
• May need to do step 4 here: https://learn.microsoft.com/en-us/windows/wsl/install-manual
• Finally set default version to WSL 2: https://learn.microsoft.com/en-us/windows/wsl/install#upgrade-version-from-wsl-1-to-wsl-2

We should add a sanity check and require this.

[jamesjuett]

One thing that's slightly imprecise in what I originally said - it's not that Ubuntu 22.04 itself is incompatible, but that with it you'll end up with a newer version of gdb that is incompatible.

I'm not sure if we'll end up with many (or any?) students who can't upgrade to WSL 2. If they're on a very old laptop, can't update to a new enough windows version, or can't enable virtualization. I haven't met any students where that's the case.

The best approach is likely to:

• Require WSL 2 in the tutorials (and add the check that wsl -l -v run from PowerShell shows version 2).
• Add instructions for upgrading from WSL 1 to WSL 2. These should probably be in a separate document that we can link to, so that they don't confuse people working through the normal setup tutorial.
• Handle any obscure cases where people are having difficulty getting WSL 2 in office hours.

[awdeorio]

Agreed!

[jamesjuett]

Just putting this here to record it somewhere. The deficit in WSL 1 is tracked here. Not clear when/if it will be fixed.