fn nextArgOrFatal(args: []const [:0]const u8, idx: *usize) [:0]const u8
fn nextArgOrFatal(args: []const [:0]const u8, idx: *usize) [:0]const u8 { return nextArg(args, idx) orelse { fatalWithHint("expected argument after {q}", .{args[idx.* - 1]}); }; }