sdk_version_constructor_tearoffs

Tearing off a constructor requires the 'constructor-tearoffs' language feature.

The analyzer produces this diagnostic when a constructor tear-off is found in code that has an SDK constraint whose lower bound is less than 2.15. Constructor tear-offs 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 2.15:

environment:
  sdk: '>=2.9.0 <2.15.0'

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

var setConstructor = Set.identity;

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

environment:
  sdk: '>=2.15.0 <2.16.0'

If you need to support older versions of the SDK, then rewrite the code to not use constructor tear-offs:

var setConstructor = () => Set.identity();

Unless stated otherwise, the documentation on this site reflects Dart 3.7.3. Page last updated on 2025-05-08. View source or report an issue.