My MacOS app only cares about days, not time-of-days, so I made a simple Date Extension: extension Date { static func ==(lhs: Date, rhs: Date) -> Bool { let order = Calendar.current.compare(lhs, to: rhs, toGranularity: .day) return (order == .orderedSame) } } My app compiles fine and works as intended. However, #Preview is failing to build the preview, erroring with: CompileDylibError: Failed to build DayRow.swift Compiling failed: ambiguous use of operator '==' @__swiftmacro_45test_calendarview_PreviewReplacement_DayRow_133_EA4566EE578D744A3A6BCC599B1B43AALl0C0fMf_.swift ------------------------------ @available(iOS 17.0, macOS 14.0, tvOS 17.0, watchOS 10.0, xrOS 1.0, *) struct $s45test_calendarview_PreviewReplacement_DayRow_133_EA4566EE578D744A3A6BCC599B1B43AALl0C0fMf_15PreviewRegistryfMu_: DeveloperToolsSupport.PreviewRegistry { static let fileID: String = "test_calendarview_PreviewReplacement_DayRow_1/DayRow.1.preview-thunk.swift" static let line: Int = 160 static let column: Int = 1 static func makePreview() throws -> DeveloperToolsSupport.Preview { DeveloperToolsSupport.Preview { @State var gDayCalTable = DayCalTable().addDummyData() @State var gSelection = Selection() return DayRow(records: gDayCalTable.records, date: Date(year: 2024, month: 1, day: 17), month: Date(), row: 0, dragCurrent: nil, dragLine: nil) .frame(width: 100, height: 20) .environment(gDayCalTable) .environment(gSelection) .padding(40) .foregroundColor(.white) } } } ------------------------------ /Users/antoine/xcode/_test/test_calendarview/test_calendarview/DayRow.swift:43:50: error: ambiguous use of operator '==' let isStart = isRange ? (dayrange!.start == date) : __designTimeBoolean("#2514.[2].[12].property.[0].[5].value.else", fallback: false) ^ /Users/antoine/xcode/_test/test_calendarview/test_calendarview/Extensions/Date.swift:31:17: note: found this candidate static func ==(lhs: Date, rhs: Date) -> Bool { ^ Foundation.Date:22:24: note: found this candidate public static func == (lhs: Date, rhs: Date) -> Bool ^ Is there something special I need to tell #Preview to have it compile successfully?