$ZED_SYMBOL doesn't really work here once that will try to do something like this: mix test MyModule.MyModuleTest instead of using the path of the file: mix test test/my_module/my_module_test.exs Release Notes: - Fix mix test $ZED_SYMBOL to use ZED_RELATIVE_FILE instead - Use ZED_RELATIVE_FILE instead of ZED_FILE to improve mix tasks results on Elixir umbrella projects