$ git clone -n https://gitee.com/src-opencloudos-rpms/libpng.git /var/lib/mock/dist-oc8-build-236132-82231/root/chroot_tmpdir/scmroot/libpng
Cloning into '/var/lib/mock/dist-oc8-build-236132-82231/root/chroot_tmpdir/scmroot/libpng'...
$ git fetch origin 776e940a6d0e972844729c0ec6c9039b8632284e:KOJI_FETCH_HEAD
From https://gitee.com/src-opencloudos-rpms/libpng
 * [new ref]         776e940a6d0e972844729c0ec6c9039b8632284e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 776e940 import libpng-1.6.34-10.tl3