Qemu-ppc Memory leak creating threads

When creating c++ threads (with c++ std::thread), the resulting binary has memory leaks when running with qemu-ppc.

Eg the following c++ program, when compiled with gcc, consumes more and more memory while running at qemu-ppc. (does not have memory leaks when compiling for Intel, when running same binary on real powerpc CPU hardware also no memory leaks).

(Note I used function getCurrentRSS to show available memory, see https://stackoverflow.com/questions/669438/how-to-get-memory-usage-at-runtime-using-c; calls commented out here)

Compiler: powerpc-linux-gnu-g++ (Debian 8.3.0-2) 8.3.0 (but same problem with older g++ compilers even 4.9)
Os: Debian 10.0 ( Buster) (but same problem seen on Debian 9/stetch)
qemu: qemu-ppc version 3.1.50



---

#include <iostream>
#include <thread>
#include <chrono>


using namespace std::chrono_literals;

// Create/run and join a 100 threads.
void Fun100()
{
//    auto b4 = getCurrentRSS();
//    std::cout << getCurrentRSS() << std::endl;
    for(int n = 0; n < 100; n++)
    {
        std::thread t([]
        {
            std::this_thread::sleep_for( 10ms );
        });
//        std::cout << n << ' ' << getCurrentRSS() << std::endl;
        t.join();
    }
    std::this_thread::sleep_for( 500ms ); // to give OS some time to wipe memory...
//    auto after = getCurrentRSS();
    std::cout << b4 << ' ' << after << std::endl;
}


int main(int, char **)
{
    Fun100();
    Fun100();  // memory used keeps increasing
}