I have a SwiftUI app that I've been working on in XCode 16.1. The project builds and runs in the simulators, on my mac and on my iPhone/iPad without any issues. I'm also able to build my unit test project and run them without any errors. The project has zero warnings in it. When I go to the Edit Schemes options and change the Run scheme to be a Release build with the Debug Executable unchecked I get a compiler error: Command SwiftCompile failed with a nonzero exit code I've attempted this Release Run with the following target devices in XCode: My iPhone 15 Pro Max (iOS 18.2 Beta 3) MacBook Air (M1) (15.2 Beta) iPhone 16 Simulator (iOS 18.1) Any iOS Simulator Device (arm64, x86_64) All 3 of these target have the same issue. Normally I would just debug the error from the logs but when I look at the build output I can't see any information in the log to tell me what happened. It looks like the source files are sent into the SwiftCompiler and the compiler fails without bubbling up the issue. I've provided the full error log export as a Gist HERE due to it's size. Is there anything in the log I'm missing? Is there a way for me to turn on more verbose logging during compilation of a Release Build? I created a brand new Multiplatform App in XCode and I added all of my source files to it. No project configuration settings were changed. I could build it successfully with the debug configuration. I then changed it to the Release configuration and experienced the same error. I can create another fresh project and make the same release configuration with none of my source files in it and get a successful build. I t seems there is something wrong with my source files and the release configuration but the compiler doesn't indicate what. I'm lost at this point as I can't figure out how to get a release build and can't seem to find any indication as to why.

I have an app with the following model: @Model class TaskList { @Attribute(.unique) var name: String // Relationships var parentList: TaskList? @Relationship(deleteRule: .cascade, inverse: \TaskList.parentList) var taskLists: [TaskList]? init(name: String, parentTaskList: TaskList? = nil) { self.name = name self.parentList = parentTaskList self.taskLists = [] } } If I run the following test, I get the expected results - Parent has it's taskLists array updated to include the Child list created. I don't explicitly add the child to the parent array - the parentList relationship property on the child causes SwiftData to automatically perform the append into the parent array: @Test("TaskList with children with independent saves are in the database") func test_savingRootTaskIndependentOfChildren_SavesAllTaskLists() async throws { let modelContext = TestHelperUtility.createModelContext(useInMemory: false) let parentList = TaskList(name: "Parent") modelContext.insert(parentList) try modelContext.save() let childList = TaskList(name: "Child") childList.parentList = parentList modelContext.insert(childList) try modelContext.save() let fetchedResults = try modelContext.fetch(FetchDescriptor<TaskList>()) let fetchedParent = fetchedResults.first(where: { $0.name == "Parent"}) let fetchedChild = fetchedResults.first(where: { $0.name == "Child" }) #expect(fetchedResults.count == 2) #expect(fetchedParent?.taskLists.count == 1) #expect(fetchedChild?.parentList?.name == "Parent") #expect(fetchedChild?.parentList?.taskLists.count == 1) } I have a subsequent test that deletes the child and shows the parent array being updated accordingly. With this context in mind, I'm not seeing these relationship updates being observed within SwiftUI. This is an app that reproduces the issue. In this example, I am trying to move "Finance" from under the "Work" parent and into the "Home" list. I have a List that loops through a @Query var taskList: [TaskList] array. It creates a series of children views and passes the current TaskList element down into the view as a binding. When I perform the operation below the "Finance" element is removed from the "Work" item's taskLists array automatically and the view updates to show the removal within the List. In addition to that, the "Home" item also shows "Finance" within it's taskLists array - showing me that SwiftData is acting how it is supposed to - removed the record from one array and added it to the other. The View does not reflect this however. While the view does update and show "Finance" being removed from the "Work" list, it does not show the item being added to the "Home" list. If I kill the app and relaunch I can then see the "Finance" list within the "Home" list. From looking at the data in the debugger and in the database, I've confirmed that SwiftData is working as intended. SwiftUI however does not seem to observe the change. ToolbarItem { Button("Save") { list.name = viewModel.name list.parentList = viewModel.parentTaskList try! modelContext.save() dismiss() } } To troubleshoot this, I modified the above code so that I explicitly add the "Finance" list to the "Home" items taskLists array. ToolbarItem { Button("Save") { list.name = viewModel.name list.parentList = viewModel.parentTaskList if let newParent = viewModel.parentTaskList { // MARK: Bug - This resolves relationship not being reflected in the View newParent.taskLists?.append(list) } try! modelContext.save() dismiss() } } Why does my explicit append call solve for this? My original approach (not manually updating the arrays) works fine in every unit/integration test I run but I can't get SwiftUI to observe the array changes. Even more strange is that when I look at viewModel.parentTaskList.taskLists in this context, I can see that the list item already exists in it. So my code effectively tries to add it a second time, which SwiftData is smart enough to prevent from happening. When I do this though, SwiftUI observes a change in the array and the UI reflects the desired state. In addition to this, if I replace my custom list rows with an OutlineGroup this issue doesn't manifest itself. SwiftUI stays updated to match SwiftData when I remove my explicit array addition. I don't understand why my views, which is passing the TaskList all the way down the stack via Bindable is not updating while an OutlineGroup does. I have a complete reproducible ContentView file that demonstrates this as a Gist. I tried to provide the source here but it was to much for the post. One other anecdote. When I navigate to the TaskListEditorScreen and open the TaskListPickerScreen I get the following series of errors: error: the replacement path doesn't exist: "/var/folders/07/3px_03md30v9n105yh3rqzvw0000gn/T/swift-generated-sources/@_swiftmacro_09SwiftDataA22UIChangeDetectionIssue20TaskListPickerScreenV9taskLists33_A40669FFFCF66BB4EEA5302BB5ED59CELL5QueryfMa.swift" I saw another post regarding these and I'm wondering if my issue is related to this. So my question is, do I need to handle observation of SwiftData models containing arrays differently in my custom views? Why do bindings not observe changes made by SwiftData but they observe changes made explicitly by me?

I have a Query in my View that brings in some data that I then filter with a few different computed properties. I then use those properties to present the data in a view. This is the view (simplified for clarity). struct FMListView: View { @Query(sort: \FMList.name) var fmLists: [FMList] private var systemTodoLists: [FMList] { fmLists.filter { $0.ownership == Ownership.system } } private var userTodoLists: [FMList] { fmLists.filter { $0.ownership == Ownership.user && $0.parentList == nil} } private var favoriteTodoLists: [FMList] { fmLists.filter { $0.isFavorite } } var body: some View { NavigationStack { List { // MARK: -- System TodoLists ForEach(systemTodoLists) { list in NavigationLink(value: list) { Text(list.name) } } Section(header: Text("Favorites").padding(.top, -24)) { ForEach(favoriteTodoLists) { list in NavigationLink(value: list) { Text(list.name) } } } // MARK: -- User TodoLists Section(header: Text("Lists").padding(.top, -24)) { ForEach(fmLists.filter { $0.ownership == Ownership.user && $0.parentList == nil}) { list in NavigationLink(value: list) { Text(list.name) } } } } .navigationDestination(for: FMList.self) { list in Text(list.name) // MARK: -- ERROR HERE Toggle(isOn: list.isFavorite) { Label("Favorite", systemImage: IconConstants.starIcon) } } } } } The challenge I have here is that I need to represent the queried data in multiple different formats (for the example, I'm just using a Text view). When I navigate to the navigationDestination I want to edit the state on a property within the model but the model in this scope isn't bindable so I can't pass it into the Toggle. I'm not sure if the issue is my use of computed properties, or if it's my not understanding binding misusing the Toggle. I'd appreciate some guidance on this use-case - allowing me to pass a bindable version of the model down the stack once filtered on the app side. On a somewhat related note - I am filtering with computed properties because I can't do this filter within the Query predicate. The following gave me a compiler error because the ownership.user wasn't a constant value. $0.ownership == Ownership.user This is what the enum looks like: enum Ownership: String, CaseIterable, Codable { case system = "SYSTEM" case user = "USER" }