add note in Settings on using WatchFiles on WSL

[danroozemond]

Following a frustrating 2hours of debugging why reloading stopped working when I rebuilt my Docker contrainer with uvicorn recently, stumbling upon @samuelcolvin 's very helpful comment on WATCHFILES_FORCE_POLLING, and @Kludex 's subtle hint that PR's are welcome to improve the documentation.... here's a PR that improves the documentation.

Relates to the discussion here: #1437

Hope it's helpful!

[samuelcolvin]

otherwise LGTM.

[samuelcolvin]

Just to be clear, WATCHFILES_FORCE_POLLING doesn't have to have any special value, it just needs to be set, set the source.

I guess we could interpret empty WATCHFILES_FORCE_POLLING as not set, but that's a pretty special case.

[danroozemond]

Thanks for the review & suggestions, @samuelcolvin , I've adopted your changed and added a link to the watchfiles documentation.

[samuelcolvin]

Great, thanks for this.

[Kludex]

you might have to set the environment variable WATCHFILES_FORCE_POLLING

Is it a "might" or you "need" to set the env variable?

[samuelcolvin]

Well, it depends on the environment, in some (e.g. docker on WSL) no changes are detected via the default file system watcher, but I don't have an finite list of environments where it does and doesn't work, hence I suggested "might" to put the decision in the hands of the developer, but up to you - I can see it either way.

[Kludex]

Thanks @danroozemond 🙏

Thanks @samuelcolvin for reviewing it 👍

[danroozemond]

Thanks for the quick review and merge, good stuff 🙂

[samuelcolvin]

Any volunteers for samuelcolvin/watchfiles#187?

[samuelcolvin]

Anyone able to review samuelcolvin/watchfiles#194 which implements the fix discussed in samuelcolvin/watchfiles#187 and confirm it has fixed this error?

I don't have a windows machine, so can't test.

[danroozemond]

@samuelcolvin thanks for making the fix! I'm happy to have a look but a bit busy the coming days. Is somewhere over the weekend OK?

[samuelcolvin]

Of course, no hurry from my pov.

Thanks.