MSYS2 Clang++ produces error with filesystem library

Question

I am using clang++, installed with MSYS2 on Windows 11. Checking the version of clang++ gives the below.

~ clang++ --version
clang version 19.1.4
Target: x86_64-w64-windows-gnu
Thread model: posix
InstalledDir: C:/msys64/mingw64/bin

The code:

#include <filesystem>

int main(){
    std::filesystem::path p = "C:/Users/Jaden/Documents/hi.txt";
    std::filesystem::path p2 = "C:/Users/Jaden";

    std::filesystem::copy(
        p, p2, std::filesystem::copy_options::overwrite_existing);
}

Produces the error:

terminate called after throwing an instance of 'std::filesystem::__cxx11::filesystem_error'
  what():  filesystem error: cannot copy: File exists [C:/Users/Jaden/Documents/hi.txt] [C:/Users/Jaden]

If I run std::filesystem::exists beforehand, it returns false. The error persists no matter if I use or do not use and copy_option flags.

The code was simply compiled with clang++ .\test.cpp.

Edit: Similarly when I compile using g++, the same issue persists.

Answer 1

After some testing, this is a bug in libstdc++, the GCC's C++ standard library. It's already fixed in the newer versions.

This happens any time you do std::filesystem::copy("file", "directory"), regardless of overwrite_existing.

I've reported it here: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118699, and was told that it's fixed in 15.x, 14.3.0, and 13.4.0, while MSYS2 still sits at 14.2.