$ git clone -n https://gitee.com/fundawang/libpng.git /var/lib/mock/dist-an23-build-173338-59009/root/chroot_tmpdir/scmroot/libpng
Cloning into '/var/lib/mock/dist-an23-build-173338-59009/root/chroot_tmpdir/scmroot/libpng'...
$ git reset --hard 87ff8d1c590b9a365b4848240f43039eb3630f48
HEAD is now at 87ff8d1 1.6.39