This one is pretty similar and slightly more readable imo (if shell-scripts can ever be considered readable). Just replace the notify-function with whatever you want to execute instead.
Different use case, but I can not recommend using Sibbell[0] enough. Especially when you have more than a handful of dependencies, tracking issues, fixes and their eventual release is crucial.
You only delay saving time and bandwidth — you eventually have to clone the repo for any ops other than checking the head SHAs and unless the repo is rarely updated, the delay will be short.
https://github.com/ianmiell/alert-on-change/blob/master/READ...
It adds the concept of degree of change to the output triggering an alert.