Description

Configuration files are handled as an option, however the envname setting does not work with them.

  app.set_config("--config")->envname("MY_CONFIG_FILE");

Additional information

Indeed the order in which we consider options shows that we consider files before environment variables. Hence the environment variable can not be taken into account.

Possible workaround

I made a workaround where I set default value of the config file, to the environment variable's value.

Expected behaviour

Make it impossible to add an environment variable to prevent confusion, or read the environment variable when we create the option in the set_config flow.