Hi, thanks for the reply.
So I realized that working with an unregistered package is what caused most of the hassle. Basically you need to develop an unregistered package like:
] dev https://github.com/biona001/IHT.jl.
which was not in the documentation, unfortunately. For other trouble shooting, I found this post helpful.
For future reference, I believe the code inside the .julia/packages/xxxx/your-package is supposed to be an environment - that is, a final code product that is there for reproducibility, and you shouldn’t be editing that code.