Diagnostic

Lints are likely to be filtered. Provide extra axes for filtering by -Wconf.

A Warning with an origin. The semantics of origin depend on the warning. For example, an unused import warning has an origin that specifies the unused selector. The origin of a deprecation is the deprecated element.

A sticky error is an error that should not be hidden by backtracking and trying some alternative path. Typically, errors issued after catching a TypeError exception are sticky.