Running a systemd-based Gentoo system

[Jack Byer]

>  Not sure about Gentoo, but Debian and Fedora have “alternatives” subsystem,
> which helps in such situation.
>
>  For specific case of ?DM, Fedora has hacky /etc/X11/prefdm script which
> is responsible for starting preffered one.
>

Gentoo has something similar and now that I think about it the only
reason this is needed is because the display manager is started by
init, not by openrc. Openrc understands virtual services so metalog,
syslog and syslog-ng can all provide the "logger" service and other
services can depend on "logger" instead of a particular logging
program. Since there's no way to represent this in /etc/inittab the
hacks are necessary for the display manager service if you're using
sysvinit.