Many, many, many things break if people leave this disabled, including many things without obvious reasons (gnome-terminal for example >:/). Reproducible: Always Steps to Reproduce: 1. 2. 3.
Well, devfs is obsoleted not only in gentoo-dev-sources, but also in vanilla development-sources. Users should be moving to udev now. Gentoo supports both and requires that one of them is present. Sooner or later devfs support will be dropped and then everyone will have to switch to udev.
Must just say that the thing breaks for a obvious reason. If you don't have anything handling /dev/ (like devfs do) then the system got lots of truble handling your devices. If you read the helptext for devfs in menuconfig it says that it is obsolete becouse of a moving towards usage of udev. But if you don't have udev installed into your system in a proper way (read the HOW-TO on www.gentoo.com under the section docs) your system will not work without devfs. Many things needs to be reworked and is under reworking (like genkernel and its initrd) before gentoo will be udev by default, but we are moving towards that. And for us using udev devfs is obsolete. My system runs without devfs compiled.
I don't think this is a bug anymore with the virtual udev / devfs issue now.
