$ git clone -n https://src.fedoraproject.org/rpms/libyuv.git /var/lib/mock/f41-build-841110-161064/root/chroot_tmpdir/scmroot/libyuv
Cloning into '/var/lib/mock/f41-build-841110-161064/root/chroot_tmpdir/scmroot/libyuv'...
$ git fetch origin 81783a2db37c5ed1771bbc37bbdd278fdb66e9bf:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libyuv
 * [new ref]         81783a2db37c5ed1771bbc37bbdd278fdb66e9bf -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 81783a2 Spec-file cleanup