Set default level

The docs recommend the following snippet to set the default level to, e.g., "warn":

env_logger::from_env(Env::default().default_filter_or("warn")).init();

However, this does not work as expected: what I would expect is that when setting RUST_LOG=some::module=info, all the other modules are still subject to the default level, "warn". However, default_filter_or says

Use the default environment variable to read the filter from.

If the variable is not set, the default value will be used.

So, once RUST_LOG is set, the default for all unspecified modules is "error" again.

Is there any way to truly change the default level for unspecified modules? If not, this is a feature request to add such an option. :)

Start with the documented env_logger::from_env(Env::default().default_filter_or("warn")) entry point and compare its behavior when RUST_LOG is unset versus some::module=info. Determine whether the existing environment-filter semantics support a separate fallback level for unspecified modules; done means the requested default behavior is defined and covered by an appropriate test or documented as unsupported.