inconsistent_language_version_override

Parts must have exactly the same language version override as the library.

The analyzer produces this diagnostic when a part file has a language version override comment that specifies a different language version than the one being used for the library to which the part belongs.

Given a part file named part.dart that contains the following:

// @dart = 2.14
part of 'test.dart';

The following code produces this diagnostic because the parts of a library must have the same language version as the defining compilation unit:

// @dart = 2.15
part 'part.dart';

Remove the language version override from the part file, so that it implicitly uses the same version as the defining compilation unit:

part of 'test.dart';

If necessary, either adjust the language version override in the defining compilation unit to be appropriate for the code in the part, or migrate the code in the part file to be consistent with the new language version.

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.