$ git clone -n https://gitee.com/fundawang/libpng.git /var/lib/mock/dist-an23-build-173330-59009/root/chroot_tmpdir/scmroot/libpng
Cloning into '/var/lib/mock/dist-an23-build-173330-59009/root/chroot_tmpdir/scmroot/libpng'...
$ git reset --hard e3c73c75d7925ee79809ab5519468478ef33a6a4
HEAD is now at e3c73c7 1.6.39