Mac: `FSEvent` ignores hard links

[emilk]

System details

• Intel MacBook running macOS BIgSur 11.6
• Using APFS
• rustc --version: 1.57.0
• Notify version: latest main

What you did (as detailed as you can)

• Watch for changes in a directory using FsEventWatcher.
• Create a file with touch foo.
• Create a hard-link using ln foo bar

What you expected

I expect to get an Event for both actions.

What happened

Only the creation of foo is reported. Nothing happens when creating the hardlink-file (bar).

Investigation

I added some logging inside of src/fsevent.rs and I get no callback when creating the hard-link, so this is likely a problem with FSEvent, or how it is being used. I tried looking for some extra flag to pass into FSEventStreamCreate, but couldn't find anything suitable.

[0xpr03]

On v5 you could test if the macos_kqueue feature gives you a better result using the kqueue backend.

[0xpr03]

According to this it could be an issue with fsevent itself.