All of a sudden, I’m facing a mysterious error that I can’t understand nor debug myself :

../../../flutter/flutter/packages/flutter/lib/semantics.dart:14:1: Error: Expected an identifier, but got 'library'.
Try inserting an identifier before 'library'.
library semantics;
^^^^^^^
../../../flutter/flutter/packages/flutter/lib/semantics.dart:1:1: Error: Expected ';' after this.
fcs// Copyright 2014 The Flutter Authors. All rights reserved.
^^^

It happened when I try to run my project on any target and affect all my other projects.

I tried to run flutter clean cache and restart my computer (that works sometimes) but nothing helped this time