libnfs changes soname with each version: https://github.com/sahlberg/libnfs/commits/master/lib/Makefile.am would be helpful to force a rebuild for media-tv/kodi with USE="nfs"
should be all set now in the tree; thanks for the report! Commit message: Add sub-slot details to track SONAME changes http://sources.gentoo.org/net-fs/libnfs/libnfs-1.9.7.ebuild?r1=1.6&r2=1.7 http://sources.gentoo.org/net-fs/libnfs/libnfs-9999.ebuild?r1=1.8&r2=1.9