Re: [PATCH v2 7/7] t/helper/simple-ipc: convert test-simple-ipc to use start_bg_command

> On Fri, 12 Nov 2021 at 16:01, Junio C Hamano <gitster@pobox.com> wrote:
> >
> > Out of curiosity, are the use cases and user base of Cygwin waning,
> > or are there still viable cases where Cygwin is a more preferred
> > solution over WSL (the question is not limited to use of Git)?
>
> No formal research here, just impressions as someone who has used
> Cygwin for a long time and who hangs out on the Cygwin mailing list:
> for a lot of use cases, WSL is at least as good, if not better, than
> Cygwin. There are a few areas where Cygwin is still a better solution,
> though:
>
> - WSL requires essentially installing an entire operating system. Disk
> space is relatively cheap, so that's not nearly the obstacle it used
> to be, but it is an obstacle. This is more relevant for people who
> want to distribute packaged installers to Windows users: most
> non-technical users won't want to get WSL working, but if you've
> written code for *nix and don't want to port it manually to Windows,
> it's relatively straightforward to compile it using Cygwin and bundle
> the cygwin1.dll file with the installer. That'll mostly get your code
> working with a user experience that doesn't differ too much from a
> fully native Windows application. (This is essentially what Git for
> Windows is doing, albeit with an increasingly distant Cygwin fork.)
>
> - There are some functions that Cygwin offers that WSL doesn't. The
> key one for me is the ability to access Windows network file shares,
> which WSL doesn't support (or at least didn't last time I checked). I
> expect some of these gaps will disappear as WSL gets more features,
> but I expect some of them are fairly fundamental restrictions: Cygwin
> applications can have code specifically to handle the fact that
> there's a Windows OS there, so they can -- with care -- interact with
> the Windows OS directly to (say) use Windows file access APIs or the
> Windows clipboard. WSL applications generally don't have that ability;
> if I install something from apt on my Debian WSL installation, it'll
> pull exactly the same binary as if I'd installed it on a normal Debian
> system. I guess in theory people could write code to detect that
> they're running in WSL and handle that specially, in the same way that
> it's normally possible to detect and handle when you're running in a
> VM versus running on bare metal. I expect that'll be much less common,
> though, just as Git has code for handling Cygwin specially but doesn't
> have code for handling Linux-within-WSL specially, even though both
> could be used to access a Git repository stored in the same Windows
> NTFS directory.