-- in.cue --
import "encoding/json"

// The reference to string needs to be included even for Visit.
a: b: json.Marshal({ #a: str })

str: "x:y:z"
-- out/dependencies/field --
"encoding/json".Marshal
str
-- out/dependencies/all --
"encoding/json".Marshal
str
-- out/dependencies/dynamic --
"encoding/json".Marshal
str