I've figured the issue on my end so thought I'd share as well in case it helps everyone out.
In my case I was trying to define the caseDisplayRepresentations for one of my App Enums dynamically using
static var caseDisplayRepresentations: [WorkoutType : DisplayRepresentation] = Dictionary<WorkoutType, DisplayRepresentation>(uniqueKeysWithValues: allCases.map { ($0, DisplayRepresentation(stringLiteral: $0.localizedName)) })
This doesn't seem to be supported by the appintentsmetadataprocessor.
I figured this out while reading the full build logs for a different reason and stumbled upon the following lines:
2023-02-11 09:29:43.852 appintentsmetadataprocessor[73327:5009856] Starting appintentsmetadataprocessor export
2023-02-11 09:29:44.041 appintentsmetadataprocessor[73327:5009856] error: At least one halting error produced during export. No AppIntents metadata have been exported and this target is not usable with AppIntents until errors are resolved.
2023-02-11 09:29:44.041 appintentsmetadataprocessor[73327:5009856] error: invalid 'caseDisplayRepresentations' for TimerNinja.WorkoutType, representations must be exhaustive and include all cases for this enum.
2023-02-11 09:29:44.042 appintentsmetadataprocessor[73327:5009856] error: cannot extract 'caseDisplayRepresentations' for TimerNinja.WorkoutType, is not a compile-time constant value