The download link for x86 on where.xml no longer works because gentoo/releases/x86/current no longer exists on distfiles.gentoo.org. Either the link needs to be redirected to autobuilds/ or the current/ symlink needs to be recreated. This error has been reported by users on #gentoo for over a day.
Have your #gentoo people look into the topic. *** This bug has been marked as a duplicate of bug 279374 ***