[OE-core] [PATCH] Windows: Enable Windows builds under WSLv2 and warn accordingly

[Richard Purdie]

On Sat, 2020-03-14 at 23:13 -0700, Alejandro Hernandez Samaniego wrote:
> Due to the architectural changes between Windows Subsystem for Linux
> v2, and WSL v1 it should now be possible to run bitbake on the
> several distros offered through the Microsoft Store.
> 
> WSLv2 is available on Windows 10 build number > 18917
> 
> The current build number may be checked by opening a cmd prompt on
> Windows and running:
> 
> C:\Users\myuser>ver
> 
> Microsoft Windows [Version 10.0.19041.113]

Thanks, this is useful information. How much of our system works on
WSL2? runqemu? testimage? eSDK? virtgl? Is anything known not to work?
This email implies everything works?

My big worry here is that we have a set subset of bugs which only occur
on WSL2. We're struggling with the bug reports we have today, adding in
a whole new set with no help to support that is a concern.

Is this for 3.1 LTS? Are Microsoft going to be able to help us in any
way? How "official" is this change?

> 
>          if "Microsoft" in l:
> -            return "OpenEmbedded doesn't work under WSL at this time, sorry"
> +            return "OpenEmbedded doesn't work under WSLv1, please upgrade to WSLv2 if you want to run builds on Windows"
> +        elif "microsoft" in l:
> +            bb.warn("You are running bitbake under WSLv2, this works properly but you should optimize your VHDX file eventually to avoid running out of storage space")
>      return None
>  
>  # Tar version 1.24 and onwards handle overwriting symlinks correctly

Is Microsoft vs microsoft the best check we can have? Should we be
checking the version specifically?

Cheers,

Richard