Elixir : Module is not loaded and could not be found

Problem When working on my recent project, I started getting the following error: module Q is not loaded and could not be found The error was shown when I run : mix test Troubleshooting I confirmed that the module was listed in the mix.exs and was installed via mix deps.get I tried iex -S mix but no error. In fact Q.q(msg) worked. I turned to Local Elixir Telegram group.