$ git clone -n https://src.fedoraproject.org/rpms/gnome-contacts.git /var/lib/mock/f42-build-side-1-3588892-46951/root/chroot_tmpdir/scmroot/gnome-contacts
Cloning into '/var/lib/mock/f42-build-side-1-3588892-46951/root/chroot_tmpdir/scmroot/gnome-contacts'...
$ git fetch origin 0fd0732e362b5f14e9b431a1d15bbe6e46387ea3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-contacts
 * [new ref]         0fd0732e362b5f14e9b431a1d15bbe6e46387ea3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0fd0732 Update to 48.0