Unbind fails in release mode on Windows using IPC transport

[mabartcz]

Issue

When using the zmq crate (version 0.10.0) on Windows, calling unbind on an IPC socket works correctly in debug mode (cargo run) but fails in release mode (cargo run --release). The code panics with:

called `Result::unwrap()` on an `Err` value: No such file or directory

This seems to indicate that unbind cannot find the path, despite it being the exact same path used in the preceding bind call.

Platform

• OS: Windows
• Crate version: zmq = "0.10.0"
• Rust: stable
• Transport: IPC

Reproduction

fn main() {
    let context = zmq::Context::new();
    let socket_path = "ipc://test_soc";

    let responder = context.socket(zmq::REP).unwrap();
    responder.bind(socket_path).unwrap();
    
    responder.unbind(socket_path).unwrap(); // <- fails in release mode
}

Cargo.toml

[dependencies]
zmq = "0.10.0"

Steps to reproduce

1. Run in debug mode (works fine):

   cargo run
   

2. Run in release mode (fails):

   cargo run --release
   

Expected Behavior

unbind should succeed in release mode just like it does in debug mode, using the same code and socket path.

Additional Notes

• This might relate to compiler optimizations, IPC path handling on Windows, or a race condition exposed only in release builds.
• The behavior is consistent and reproducible.
• If I try this with TCP, inproc, it works.
• If I try this using C++, it works.

Please let me know if further diagnostics or logs are needed.