SelectorCollisionError

The Cause

Two Transactions in the loaded API description render the same Selector, so neither can be addressed unambiguously.

A Selector is host-stripped and carries no query parameters or headers, so two Transactions collide whenever they agree on method, path, status and media types — whether they come from one description or two.

The most common cause is loading two descriptions of the same API, for example a staging and a production document.

What to do

The error names both sides, with each one’s source and — where the description carries the position — its file and line. Then:

• If the two point at different documents, load those sources separately. There is no way to say “the one from staging” in a Selector.
• If they point at one document, give the two operations distinct paths, methods, statuses or media types.

Nothing is dropped or resolved “last wins”: which one a hook would have bound to would depend on load order, which is not a thing anyone can reason about.