app-backup/snapper works well and reliable on many of my amd64 keyworded servers. Please stabilize a version of your choice, snapper deserves it. I propose 0.5.4. And please think about moving app-backup/snapper to sys-fs/snapper - IMHO it is a system tool, not a backup application.
No maintainer reaction, so I start the stabilisation request...
double-edit clash - I forgot to specify latest version. This was not intended, sorry.
x86 stable
amd64 stable