Portage version is still 0.8.0, please bump to latest upstream one. Reproducible: Always
+*xf86-input-libinput-0.11.0 (23 Jun 2015) + + 23 Jun 2015; Gilles Dartiguelongue <eva@gentoo.org> + +xf86-input-libinput-0.11.0.ebuild: + Version bump, bug #551926. + 0.17 is the libinput library, not the x11 driver. Thanks for reporting.