feat: allow for disabling crossbeam-channel

[raphaelcoeffic]

As it turns out, tokio does not mix well with notify when crossbeam-channels are enabled (see here).

In my tests with yaque added this way to my deps, it seems to work as expected (with this PR in place):

yaque = { version = "0.6.6", default-features = false, features = ["no-crossbeam-channel"] }

Fixes #32

[tokahuke]

I can't believe it's that simple! Do you have any resources on this funky behavior?

EDIT: Sorry! I saw the link in your comment.

[alexander-camuto]

wow

[tokahuke]

So, I will merge and create a new minor version tomorrow, when I have some time to look into this closely.

[raphaelcoeffic]

So, I will merge and create a new minor version tomorrow, when I have some time to look into this closely.

Thx a lot for your time!

[tokahuke]

So, what has made me a bit uneasy was this: every time we compile for a MacOS target we would have to use this no-crossbeam-feature? Could we use [target.'cfg(target_os = "macos")'.dependencies] instead? (I have googled and it says this is a bit broken, but at least worth a shot. Else, could we use. cfg in the code directly?)

[raphaelcoeffic]

I thought about that at first, and it did work as well, but I believe it is actually related to using the tokio runtime rather than macOS. I did not test this under Linux though to confirm if this really the case.

The reason why it is needed to require kqueue is because notify does not provide a default for macOS if you don't use the default feature.