const_constructor_with_non_const_super

A constant constructor can't call a non-constant super constructor of '{0}'.

The analyzer produces this diagnostic when a constructor that is marked as const invokes a constructor from its superclass that isn't marked as const.

The following code produces this diagnostic because the const constructor in B invokes the constructor nonConst from the class A, and the superclass constructor isn't a const constructor:

class A {
  const A();
  A.nonConst();
}
​
class B extends A {
  const B() : super.nonConst();
}

If it isn't essential to invoke the superclass constructor that is currently being invoked, then invoke a constant constructor from the superclass:

class A {
  const A();
  A.nonConst();
}
​
class B extends A {
  const B() : super();
}

If it's essential that the current constructor be invoked and if you can modify it, then add const to the constructor in the superclass:

class A {
  const A();
  const A.nonConst();
}
​
class B extends A {
  const B() : super.nonConst();
}

If it's essential that the current constructor be invoked and you can't modify it, then remove const from the constructor in the subclass:

class A {
  const A();
  A.nonConst();
}
​
class B extends A {
  B() : super.nonConst();
}