Inotify can raise some errors if init is too fast

[samoht]

See https://github.com/dsheets/ocaml-inotify-event/blob/master/src/inotify_events.ml#L38

The fix is too run:

    (* Block until there is something to read. Otherwise, our ioctl
       returns 0 and then makes a 0 read which errors with EINVAL. *)
    ignore (Unix.select [inotify] [] [] ~-.1.);

before calling Inotify.read

[samoht]

/cc @dsheets (who wrote that bit of code) and @whitequark (who maintain the upstream inotify bindings)

[dsheets]

I think you mean @whitequark...