Swift import Error,Those are error message

[IosSuperman]

Undefined symbol: nominal type descriptor for FeedKit.RSSFeedItem

Undefined symbol: protocol conformance descriptor for FeedKit.ParserError : Swift.Error in FeedKit

Undefined symbol: FeedKit.FeedParser.__allocating_init(URL: Foundation.URL) -> FeedKit.FeedParser

Undefined symbol: type metadata accessor for FeedKit.RSSFeedItem

Undefined symbol: type metadata accessor for FeedKit.FeedParser

Undefined symbol: type metadata for FeedKit.ParserError

[GarthSnyder]

What platform? What versions? What context?

[briannadoubt]

I would guess your Podfile or package isn't set up right, but from a "reference not found" error, could be a myriad of things.