It seems that the ${PN}-0.1.0-autodetect.patch adds conditionals to fix automagic dependencies. But at the same time, there's no code setting those conditionals...
+*nsgenbind-0.1.1 (15 Nov 2014) + + 15 Nov 2014; Michael Weber <xmw@gentoo.org> + +files/nsgenbind-0.1.1-glibc2.20.patch, +nsgenbind-0.1.1.ebuild: + Version bump, buildsystem bump, glibc-2.20 issue, respect USE-flags (thanks + mgorny, bug 513598) +