$ git clone -n https://src.fedoraproject.org/rpms/m1n1.git /var/lib/mock/f39-build-1524379-36032/root/chroot_tmpdir/scmroot/m1n1
Cloning into '/var/lib/mock/f39-build-1524379-36032/root/chroot_tmpdir/scmroot/m1n1'...
$ git fetch origin 057de87823608b5b0f4a8733e542460293709b15:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/m1n1
 * [new ref]         057de87823608b5b0f4a8733e542460293709b15 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 057de87 Update to 1.4.3