Consider the following code, adapted from the repro for #36511:

enum Foo {
  bar,
  baz
}
main() {
  const x = Foo.bar == Foo.baz;
  print(x);
}

This code is erroneous, because Foo.bar == Foo.baz is not a valid constant expression. Equality checks in constant expressions may only be used to compare primitive types; they may not be used to compare user-provided types such as Foo.

The analyzer correctly detects the error, reporting:

error • In constant expressions, operands of this operator must be of type 'bool', 'num', 'String' or 'null' at .../test.dart:6:13 • const_eval_type_bool_num_string

But the VM executes the code without complaint.

(I'm classifying this bug as both area-vm and area-front-end because I'm not sure whether the VM has been transitioned over to using the front end's constant evaluator yet. Feel free to reassign as appropriate.)