How best to use a custom module?

[lawless-m]

The use of multiple includes is what’s causing the problem.

You could try this where they are all in the same source file

Getting ERROR: LoadError: UndefVarError: Environment not defined when I try to use the modules I created

Judicious use of import, using and export (the include makes no difference, it is just text subsitution) module Environment export Env mutable struct Env distance_from_pasture::Real trips_milking_parlor::Integer topography::String end end using .Environment export Env module Cows import ..Env export Cow mutable struct Cow environment::Env end end using .Cows export Cow e = Env(1, 1, "") c = Cow(e)

Or add moduleA to the Manifest of moduleB using Pkg.add(path=“/path/to/A”), create a project in a separate directory to include moduleA and moduleB as dependencies.