Why is GCC throwing filesystem_error cannot copy

Question

I'm working on an app that writes/copies files and thought of updating the code to C++17's filesystem.

I'm on Windows 11 using g++ v12.2 with MSYS2 MinGW 64-bit.

Below is a summary of my app's behavior.

#include <cstdlib>
#include <iostream>
#include <fstream>
#include <filesystem>
namespace fs = std::filesystem;
 
int main() {
    fs::create_directories("sandbox");
    
    std::ofstream ofs;
    ofs.open ("sandbox/file1.txt", std::ofstream::out | std::ofstream::app);
        ofs << "hello";
    ofs.close();
    
    std::cout << "test copy file" << std::endl;
    fs::copy("sandbox/file1.txt", "sandbox/file2.txt", fs::copy_options::overwrite_existing); // copy file
    
    static_cast<void>(std::system("tree"));
    
    //sometime later, file is updated
    ofs.open ("sandbox/file1.txt", std::ofstream::out | std::ofstream::app);
        ofs << "world";
    ofs.close();
    
    //sometime later, need to update file2 via copy
    std::cout << "test copy file again" << std::endl;
    fs::copy("sandbox/file1.txt", "sandbox/file2.txt", fs::copy_options::overwrite_existing); // copy file

    fs::remove_all("sandbox");
}

Above code was compiled with:

g++ -c -std=gnu++17 testcopy.cpp -o testcopy.o
g++ ./testcopy.o  -o testcopy.exe

Then, you'll get this:

./testcopy.exe
test copy file
Folder PATH listing for volume Acer
Volume serial number is 38B3-48F3
C:.
└───sandbox
test copy file again
terminate called after throwing an instance of 'std::filesystem::__cxx11::filesystem_error'
  what():  filesystem error: cannot copy: File exists [sandbox/file1.txt] [sandbox/file2.txt]

I wonder if I have to release, free, or close file2.txt after first copy but I don't know how.

Or, possibly, copy_options is not supported by GCC on Windows, to which I'm okay defer porting my code to C++17.

I was expecting copy_options::overwrite_existing will handle the File exists problem. I've also used copy_options::update_existing to no avail.