sys-libs/tevent-0.9.17 was released on 2012/08/17. It happens to be a prerequisite to samba-4.0.0rc1. For me, renaming the ebuild for 0.9.16 and dropping the obsolete PATHCHES=( "${FILESDIR}"/add-py-file.patch ) line just worked. Please, bump. Reproducible: Always
In portage