R-packages_src_install() { insinto /usr/$(get_libdir)/R/site-library doins -r "${WORKDIR}"/${PN//_/.}y } should be R-packages_src_install() { insinto /usr/$(get_libdir)/R/site-library doins -r "${WORKDIR}"/${PN//_/.} }
Fixed in https://gitweb.gentoo.org/proj/R_overlay.git/commit/?id=9cbd621514659738f3a8943e4bde3d90c8febfc3 Thank you Sora for the report.