$ git clone -n https://src.fedoraproject.org/rpms/gnome-calendar.git /var/lib/mock/f41-build-side-1-2925277-35001/root/chroot_tmpdir/scmroot/gnome-calendar
Cloning into '/var/lib/mock/f41-build-side-1-2925277-35001/root/chroot_tmpdir/scmroot/gnome-calendar'...
$ git fetch origin c843aaae7773bc7b0bb861f824a230cca2263678:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-calendar
 * [new ref]         c843aaae7773bc7b0bb861f824a230cca2263678 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c843aaa Update to 47.0