In supervise-scripts (both 3.4 and 3.5) conf-bin is by default /usr/local/bin but the ebuilds install the binaries to /usr/bin, this breaks the svscan-add-to-inittab script. I also added svscan-start and svscan-stopall to dobin in the 3.4 ebuild (it's okay in 3.5), since those are needed by the svscan-add-to-inittab script. While I was at it I also included dodoc and doman in 3.4.
Created attachment 17614 [details, diff] supervise-scripts-3.4.ebuild patch
Created attachment 17615 [details, diff] supervise-scripts-3.5.ebuild patch
Committed.