Yup, that's me :) For example in the `procfs` crate, there's a dependency on `flate2` just in case a /boot/config.gz file exists (in order to see what options

Yup, that's me :) For example in the `procfs` crate, there's a dependency on `flate2` just in case a /boot/config.gz file exists (in order to see what options the kernel was built with). But if a consumer never needs to inspect the kernel options, this dependency (and related code) is just dead-weight. The nice thing about rust is that this code will be removed from the final executable if it's unused, but maybe it's time to start thinking more carefully about compile times.