Local path dependencies are described here: mix deps — Mix v1.20.2

For cases like that, I’d sometimes do the following:

defp deps() do
  [
    ecto: ecto_dep()
  ]
end

defp ecto_dep() do
  if path = System.get_env("ECTO_PATH") do
    {:ecto, path: path}
  else
    {:ecto, "~> 3.0"}
  end
end

Figured it out. If you’re using path dep and dont want to have to start stop your phoenix app to have changes reflected you just need to add the path to elixirc_paths in mix.exs e.g.

  # Specifies which paths to compile per environment.
  defp elixirc_paths(:test), do: ["lib", "test/support"]
  defp elixirc_paths(_), do: ["lib", "/Path/to/dependency"]