$ git clone -n https://src.fedoraproject.org/rpms/mailx.git /var/lib/mock/f40-build-2296829-56417/root/chroot_tmpdir/scmroot/mailx
Cloning into '/var/lib/mock/f40-build-2296829-56417/root/chroot_tmpdir/scmroot/mailx'...
$ git fetch origin 4147eba36e6d8f22c9ffdd58ea66bd1fde85c965:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mailx
 * [new ref]         4147eba36e6d8f22c9ffdd58ea66bd1fde85c965 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4147eba Obsoleted by s-nail