0) this is for bug 816303 and its fallout
   https://bugs.gentoo.org/816303 

1) for this to even have a chance of working, systemd-tmpfiles needs to be
   in *stage1* (otherwise it can't be called at the start of the stage3
   build).

Since we can perfectly add whole systemd to packages.build, adding only
systemd-tmpfiles on openrc stages is no big deal (I checked, it works).

2) systemd-tmpfiles only does as much as its already present config says

Which means we get an additional hook, but it's not doing too much yet.
I hope it's enough, so far I rebuilt stages 4 times with different package
sets and did not see any failures yet.

-- 
Andreas K. Hüttel
dilfridge@gentoo.org
Gentoo Linux developer
(council, toolchain, base-system, perl, libreoffice)