$ git clone -n https://src.fedoraproject.org/rpms/gnome-disk-utility.git /var/lib/mock/f40-build-790375-136512/root/chroot_tmpdir/scmroot/gnome-disk-utility
Cloning into '/var/lib/mock/f40-build-790375-136512/root/chroot_tmpdir/scmroot/gnome-disk-utility'...
$ git fetch origin 6586e393a44ba7a1d7f5c7ad6e15fff71dbe3fe1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-disk-utility
 * [new ref]         6586e393a44ba7a1d7f5c7ad6e15fff71dbe3fe1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6586e39 Update to 46.alpha