How to create tests for System.cmd and Port when is compiling with mix

Hello, I hope you are well.
Two years ago I created a lib ( mishka_installer ) that compiles a hex pkg lib in another path and move bin (builded) files to the build dir and start the apps with some considerations.

Now I totally change my lib and refactor it after 2 years.

My new pull request that I am re-writing my lib:

Refactor and Rewriting the Mishka installer project with Erlang’s built-in databases - 0.1.0


What is my question?

As you know, compiling a lib takes time, which is long!!

Sometimes more than 3 or 4 min especially you want to compile 3 or 4 apps in a queue and I don’t know how much they take!?

So for these tests what you suggest to do?

Thank you in advance