$ sudo apt-get update
$ sudo apt-get install libinotify-ocaml 

libinotify-ocaml is installed in your system.

Make ensure the libinotify-ocaml package were installed using the commands given below,

$ sudo dpkg-query -l | grep libinotify-ocaml *

You will get with libinotify-ocaml package name, version, architecture and description in a table

libinotify-ocaml package basic information: