Proc

According to [this](https://stackoverflow.com/a/64122275/3332686) it could be an issue with fsevent itself.

I can't debug this as I don't own any mac systems. If someone wants to take this issue I could help guiding through the code.

@dhiemaz first of all reproducing the mentioned bug would be nice, then you could try to figure out if we've got an logic error inside [fsevent](https://github.com/notify-rs/notify/blob/main/src/fsevent.rs) by tracing through the...

@Skyxim did you use the default features or did you specify another backend ? (see above)

Is this fixed by #409 ?

On which system did you get this to deadlock ?

I've got no real stakes in this, we've had no problems with them being public so far. Also your current implementation adds an additional .clone - though its probably irrelevant....

Question is what do we do when you block the watcher ? Simply buffer the events or just drop them ? Also this may be different between debounced and edge...

The bad part: if we want to name the feature `crossbeam-channel`, as used in notify, we'll have to raise the MSRV to 1.60. So this is my workaround.

CC @JohnTitor for pro/contra