Add and develope an unregistered local package

I am trying to update a discontinued package called MatlabCompat.jl.
First, I ran my forked FemtoCleaner locally to update the deprecated syntax, and here is the result: Updated MatlabCompat.jl.

However, as I mentioned here in my pull request, I can not add the updated package, and I get errors for “Unsatisfiable requirements detected for package Tk”.

My question is: How can I add a package like this and debug and test its various aspects. It seems very hard to be able to update the syntax inside a package without having a way to test it.

What I usually do is to clone my package into the .julia/dev using git and then do dev MyPackage in package mode.

For other paths, you should be able to use

(v1.1) pkg> dev path/to/mypackage