Created attachment 377400 [details] build.log snapper won't build with =sys-fs/btrfs-progs-3.14.1. It works with =sys-fs/btrfs-progs-3.14.1-r1, however.
Created attachment 377402 [details] emerge --info
*btrfs-progs-3.14.1-r1 (20 May 2014) 20 May 2014; Mike Gilbert <floppym@gentoo.org> +btrfs-progs-3.14.1-r1.ebuild, +files/btrfs-progs-3.14.1-arg_strtou64.patch: Backport patch to fix linking failures with libbtrfs, reported by dlan. then, please just install btrfs-progs-3.14.1-r1, don't bother with 3.14.1
Seems to me like there should be a blocker on that version while it still exists in the tree.