$ git clone -n https://src.fedoraproject.org/rpms/libzypp.git /var/lib/mock/f40-build-769663-125734/root/chroot_tmpdir/scmroot/libzypp
Cloning into '/var/lib/mock/f40-build-769663-125734/root/chroot_tmpdir/scmroot/libzypp'...
$ git fetch origin f7b7ee67518828443477794c30c35d6c555df3bc:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libzypp
 * [new ref]         f7b7ee67518828443477794c30c35d6c555df3bc -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f7b7ee6 Rebuild against rpm-4.19 (https://fedoraproject.org/wiki/Changes/RPM-4.19)