ERROR: approachs60: Picker/source/pickers/ColorPicker.mc:60: Cannot override parameter 1 of '$.Toybox.WatchUi.PickerDelegate.onAccept' with type '$.Toybox.Lang.Array<$.Toybox.Lang.Number>'.
ERROR: approachs60: Picker/source/pickers/DatePicker.mc:56: Cannot override parameter 1 of '$.Toybox.WatchUi.PickerDelegate.onAccept' with type '$.Toybox.Lang.Array<Null or $.Toybox.Lang.Number>'.
ERROR: approachs60: Picker/source/pickers/StringPicker.mc:112: Cannot override parameter 1 of '$.Toybox.WatchUi.PickerDelegate.onAccept' with type '$.Toybox.Lang.Array<$.Toybox.Lang.String>'.
ERROR: approachs60: Picker/source/pickers/TimePicker.mc:122: Cannot override parameter 1 of '$.Toybox.WatchUi.PickerDelegate.onAccept' with type '$.Toybox.Lang.Array<Null or $.Toybox.Lang.Number>'.
The error message could be much clearer. In particular, it should say what an acceptable type *would* be. Looking up PickerDelegate.onAccept, it expects an Array argument, so the error does seem to be correct.
It looks like the type checker has tightened up argument checking for override methods (maybe as a response to https://forums.garmin.com/developer/connect-iq/i/bug-reports/issues-with-the-type-checker-and-covariant-arguments ?). I tried an experiment, and it seems that now the type checker requires the override to exactly match, which is stronger than necessary - it should (or could, at any rate) accept any type that Array is a subtype of (so eg "Object", or "Array or Dictionary"). But at any rate, it's correct to reject a strict subtype of Array.
So the bug here is that the Picker project needs fixing.
While Im here I'll also note that Selectable is still broken as reported here
