[bisubus]

Cancellation no longer appears in declared failure types. A promise typed CancelablePromise<T, E> now reports only E, and the cancel reason stays a runtime concern, so a catch handler sees the declared failures and nothing else.

The failure helpers are simpler to call. withFailure takes several failure types and error matchers, and fail declares the failure it rejects with, so CancelablePromise.fail(error) and LazyPromise.fail(error) need no options argument. A rethrowing or translating catch keeps the failures it declared.

The open set of failures is explicit. Unlisted marks a failure set as open, and an already open set keeps one marker instead of listing it twice. Native promises read as Unlisted, and TOrUnlisted leaves a closed set closed.

Lazy promises strip cancellation from their failure carrier, so LazyPromise failures match CancelablePromise failures.

Breaking changes are listed in the changelog with migration notes for each affected package.