unqualified_reference_to_non_local_static_member

Static members from supertypes must be qualified by the name of the defining type.

The analyzer produces this diagnostic when code in one class references a static member in a superclass without prefixing the member's name with the name of the superclass. Static members can only be referenced without a prefix in the class in which they're declared.

The following code produces this diagnostic because the static field x is referenced in the getter g without prefixing it with the name of the defining class:

class A {
  static int x = 3;
}
​
class B extends A {
  int get g => x;
}

Prefix the name of the static member with the name of the declaring class:

class A {
  static int x = 3;
}
​
class B extends A {
  int get g => A.x;
}