The newest wireguard version fails to build because it fails to apply a patch defined in the ebuild: PATCHES=( "${FILESDIR}/${P}-sch_generic-header.patch" ) However, only wireguard-modules-1.0.20200426-sch_generic-header.patch (for the previous version) is present in the files directory for the ebuild. It seems like the patch was created to solve https://bugs.gentoo.org/717582 and may no longer be needed for the updated version. Reproducible: Always
Made a small copy-and-paste error: The patch file wireguard-modules-1.0.20200413-sch_generic-header.patch is present, the file wireguard-modules-1.0.20200426-sch_generic-header.patch is missing.
https://bugs.gentoo.org/719778 is probably a duplicate