Add note about doing stuff after StartCause::Init on macOS

README.md

@@ -129,3 +129,16 @@ fn main() {
 ```
 
 And run the application with `cargo apk run --example request_redraw_threaded`
+
+#### MacOS
+
+A lot of functionality expects the application to be ready before you start
+doing anything; this includes creating windows, fetching monitors, drawing,
+and so on, see issues [#2238], [#2051] and [#2087].
+
+If you encounter problems, you should try doing your initialization inside
+`Event::NewEvents(StartCause::Init)`.
+
+[#2238]: https://github.com/rust-windowing/winit/issues/2238
+[#2051]: https://github.com/rust-windowing/winit/issues/2051
+[#2087]: https://github.com/rust-windowing/winit/issues/2087