sdk_version_set_literal

Set literals weren't supported until version 2.2, but this code is required to be able to run on earlier versions.

The analyzer produces this diagnostic when a set literal is found in code that has an SDK constraint whose lower bound is less than 2.2.0. Set literals weren't supported in earlier versions, so this code won't be able to run against earlier versions of the SDK.

Here's an example of a pubspec that defines an SDK constraint with a lower bound of less than 2.2.0:

environment:
  sdk: '>=2.1.0 <2.4.0'

In the package that has that pubspec, code like the following produces this diagnostic:

var s = <int>{};

If you don't need to support older versions of the SDK, then you can increase the SDK constraint to allow the syntax to be used:

environment:
  sdk: '>=2.2.0 <2.4.0'

If you do need to support older versions of the SDK, then replace the set literal with code that creates the set without the use of a literal:

var s = new Set<int>();

Unless stated otherwise, the documentation on this site reflects Dart 3.8.1. Page last updated on 2025-05-08. View source or report an issue.