Do you mean adding new values to an enum nested in an interface like this:

interface Foo {
  [Extensible]
  enum Bar {
    v0,
    [MinVersion=1]v1
  };

  SendBar(Bar bar);
};

The enum is currently considered as a separate type, so it won't affect the interface's versioning. It is similar to:

[Extensible]
enum Foo_Bar {
  v0,
  [MinVersion=1]v1
};

interface Foo {
  SendBar(Foo_Bar bar);
};

Does it affect your use case in any significant way? I would be happy to learn about. Thanks!

I used second case you described. Real example is here: https://codereview.chromium.org/2723263003/diff/60001/components/arc/common/auth.mojom

This is not blocker for us and we can handle this acceptable way.

Thanks for the info, Yury!

Btw, in case you didn't notice, [MinVersion] doesn't really have any effect on enums, except for documentation purposes. For enum versioning, the attribute [Extensible] is the only thing that matters.

Great, thank you for explanations! Please feel free to update this bug way you think.

Closing based on the discussion.