pub fn failingDirOpenDir(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8, options: Dir.OpenOptions) Dir.OpenError!Dir
pub fn failingDirOpenDir(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8, options: Dir.OpenOptions) Dir.OpenError!Dir { _ = userdata; _ = dir; _ = sub_path; _ = options; return error.FileNotFound; }