$ git clone -n https://src.fedoraproject.org/rpms/rubygem-sprockets.git /var/lib/mock/f45-build-35333-694/root/chroot_tmpdir/scmroot/rubygem-sprockets
Cloning into '/var/lib/mock/f45-build-35333-694/root/chroot_tmpdir/scmroot/rubygem-sprockets'...
$ git fetch origin 8a779bad1fad6f4366d524891a840ab658ab51f3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-sprockets
 * [new ref]         8a779bad1fad6f4366d524891a840ab658ab51f3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8a779ba Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild