$ git clone -n https://src.fedoraproject.org/rpms/gnome-calendar.git /var/lib/mock/f41-build-852873-166508/root/chroot_tmpdir/scmroot/gnome-calendar
Cloning into '/var/lib/mock/f41-build-852873-166508/root/chroot_tmpdir/scmroot/gnome-calendar'...
$ git fetch origin 531418b2a515844bc7401dd1b43828fbb9faaf80:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-calendar
 * [new ref]         531418b2a515844bc7401dd1b43828fbb9faaf80 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 531418b Update to 47.rc