$ git clone -n https://src.fedoraproject.org/rpms/rubygem-dnsruby.git /var/lib/mock/f45-build-34881-692/root/chroot_tmpdir/scmroot/rubygem-dnsruby
Cloning into '/var/lib/mock/f45-build-34881-692/root/chroot_tmpdir/scmroot/rubygem-dnsruby'...
$ git fetch origin 889f9d0bc8c47b7ea1f0e4ddb3ac7ac4c8e71056:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-dnsruby
 * [new ref]         889f9d0bc8c47b7ea1f0e4ddb3ac7ac4c8e71056 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 889f9d0 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild