pub fn php_lib(&self, is_debug: bool) -> PathBuf {
        let php_lib_path = std::env::var("PHP_LIB")
            .map(PathBuf::from)
            .unwrap_or_else(|_| self.0.join("lib"));

        if !php_lib_path.exists() {
            panic!(
                "Error: Specified PHP library path '{}' does not exist.",
                php_lib_path.display()
            );
        }

        let candidates = if is_debug {
            ["php8_debug.lib", "php8ts_debug.lib"]
        } else {
            ["php8.lib", "php8ts.lib"]
        };

        candidates
            .iter()
            .map(|lib| php_lib_path.join(lib))
            .find(|path| path.exists())
            .expect(&format!(
                "{}",
                if is_debug {
                    format!(
                        r#"Error: No suitable PHP library found in '{}'.
To build the application in DEBUG mode on Windows,
you must have a PHP SDK built with the DEBUG option enabled
and specify the PHP_LIB to the folder containing the lib files.
For example: set PHP_LIB=C:\php-sdk\php-dev\vc16\x64\php-8.3.13-src\x64\Debug_TS."#,
                        php_lib_path.display()
                    )
                } else {
                    format!(
                        "Error: No suitable PHP library found in '{}'.",
                        php_lib_path.display()
                    )
                }
            ))
    }
Returns the path of the PHP library containing symbols for linking.
windows_build.rs