fatal error: svgpp/policy/xml/rapidxml_ns.hpp

[Jxpenggf]

Hello, I want to install this library，so I download it by git clone --recurse-submodules https://github.com/cpp-io2d/P0267_RefImpl
then
cd P0267_RefImpl
mkdir build
cmake ..
make
it made an error in the make process
fatal error: svgpp/policy/xml/rapidxml_ns.hpp: Without that file or directory
#include <svgpp/policy/xml/rapidxml_ns.hpp>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~