Process.V2 may block with wrong way use of "process_stdio"

[atomictoquark]

#define WIN32_LEAN_AND_MEAN
#define BOOST_PROCESS_VERSION 2
#include <boost/process.hpp>
#include <iostream>

#if defined(BOOST_PROCESS_V2_WINDOWS)
#pragma comment(lib,"ntdll.lib")

//for MSVC 143
#if defined(_MT) //MultiThread Static
#   if defined(_DEBUG)
#       pragma comment(lib,"libboost_process-vc143-mt-sgd-x64-1_87.lib")
#   endif
#endif
#endif

using namespace boost;
namespace bp = boost::process::v2;
int main()
{
    asio::io_context ctx;
    std::string output;
    output.resize(1000);
    system::error_code ec;

    {
        //bad way
        asio::readable_pipe rp2{ ctx };

        //this io must declare inside proc like bp::process proc(ctx,xx,xxx,bp::process_stdio{{...},{...},{..}}}
        bp::process_stdio io = bp::process_stdio{ nullptr, rp2, nullptr };
        //due to process_io_binding@stdio.hpp hold this pip handle with a unique_ptr,
        //this make the life time as long as the var 'proc' bellow
        //and cannot clean the handle passed to the child,after CreateProcessW
        //thus read_some can't get ERROR_PIPE_BROKEN(because there still have a valid PIPE handle in 'io')

        //use SysinternalsSuite/procexp64 FIND->FIND Handle or DLL to search 'asio' 
        //after child process exit.it should not valid.
        bp::process proc(ctx, R"(C:\Program Files\Git\bin\git.exe)", { "-v" }, io);
        proc.detach();
        while (true)
        {
            //bad:never revice ERROR_PIPE_BROKEN
            auto size = rp2.read_some(asio::buffer(output), ec);
            if (ec)  break;
            std::cout<<output.substr(0, size);
        }
        std::cout<<"badend\n\n";
    }

    {
        //good way
        asio::readable_pipe rp{ ctx };
        bp::process proc(ctx, R"(C:\Program Files\Git\bin\git.exe)", { "-v" }, bp::process_stdio{ nullptr, rp, nullptr });
        proc.detach();
        while (true)
        {
            auto size = rp.read_some(asio::buffer(output), ec);
            if (ec)  break;
            std::cout<<output.substr(0, size);
        }
        std::cout<<"goodend\n\n";
    }

    return 0;
}

[klemens-morgenstern]

What's the issue?

[atomictoquark]

//bad:never revice ERROR_PIPE_BROKEN
auto size = rp2.read_some(asio::buffer(output), ec);
situation:will not return when child process exited.bolcked here.
except: return with ec(ERROR_PIPE_BROKEN) when child process exited.
reason:io hold the pipe handle passed to child(created by CreateFileW),it should be closed after CreateProcessW imediately,but now its in io's unique_ptr.
diffrent between bad-good:good way correctly called ~process_io()
bad way move contructor not called,so native handle lifetime is too long to make the problem.