PHPStorm: Don't show "External file changes sync may be slow" notification
I run and develop my web projects within a vertical machine. Therefore I have the project as external volume in Finder. PHPStorm complains about that fact because it can't work with file watchers for those projects. When running into this "error message" every single time, it's getting annoying. Here is how to fix it:
Open Settings, then Notifications and disable "File Watcher" there.