Function run

crates/venvlauncher/src/main.rs:25–72

()

}

fn run() -> Result<u32, Box<dyn core::error::Error>> {
    // 1. Get own executable path
    let exe_path = env::current_exe()?;
    let exe_name = exe_path
        .file_name()
        .ok_or("Failed to get executable name")?
        .to_string_lossy();

    // 2. Determine target executable name based on launcher name
    // pythonw.exe / venvwlauncher -> pythonw.exe (GUI, no console)
    // python.exe / venvlauncher -> python.exe (console)
    let exe_name_lower = exe_name.to_lowercase();
    let target_exe = if exe_name_lower.contains("pythonw") || exe_name_lower.contains("venvw") {
        "pythonw.exe"
    } else {
        "python.exe"
    };

    // 3. Find pyvenv.cfg
    // The launcher is in Scripts/ directory, pyvenv.cfg is in parent (venv root)
    let scripts_dir = exe_path.parent().ok_or("Failed to get Scripts directory")?;
    let venv_dir = scripts_dir.parent().ok_or("Failed to get venv directory")?;
    let cfg_path = venv_dir.join("pyvenv.cfg");

    if !cfg_path.exists() {
        return Err(format!("pyvenv.cfg not found: {}", cfg_path.display()).into());
    }

    // 4. Parse home= from pyvenv.cfg
    let home = read_home(&cfg_path)?;

    // 5. Locate python executable in home directory
    let python_path = PathBuf::from(&home).join(target_exe);
    if !python_path.exists() {
        return Err(format!("Python not found: {}", python_path.display()).into());
    }

    // 6. Set __PYVENV_LAUNCHER__ environment variable
    // This tells Python it was launched from a venv
    // SAFETY: We are in a single-threaded context (program entry point)
    unsafe {
        env::set_var("__PYVENV_LAUNCHER__", &exe_path);
    }

    // 7. Launch Python with same arguments
    let args: Vec<String> = env::args().skip(1).collect();
    launch_process(&python_path, &args)
}

/// Parse the `home=` value from pyvenv.cfg
fn read_home(cfg_path: &Path) -> Result<String, Box<dyn core::error::Error>> {