$ git clone -n https://gitee.com/opencloudos-stream/libpng12.git /var/lib/mock/dist-oc9-epol-build-82721-57140/root/chroot_tmpdir/scmroot/libpng12
Cloning into '/var/lib/mock/dist-oc9-epol-build-82721-57140/root/chroot_tmpdir/scmroot/libpng12'...
$ git fetch origin master:KOJI_FETCH_HEAD
From https://gitee.com/opencloudos-stream/libpng12
 * [new branch]      master     -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0b82fd2 package init