$ git clone -n https://src.fedoraproject.org/rpms/gnome-system-monitor.git /var/lib/mock/f41-build-836897-158940/root/chroot_tmpdir/scmroot/gnome-system-monitor
Cloning into '/var/lib/mock/f41-build-836897-158940/root/chroot_tmpdir/scmroot/gnome-system-monitor'...
$ git fetch origin 787a3b78726e922917b728c30b24bcf66dbd0d54:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-system-monitor
 * [new ref]         787a3b78726e922917b728c30b24bcf66dbd0d54 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 787a3b7 Update to 47.beta