I don't see anything that particularly stands out in the code you provided, but if I were to hazard a guess here, it might be a problem with LoginView or MainTabView. If you're creating a toolbar with the toolbar modifier, and you're mixing and matching IDs, you'll need to make sure each toolbar item has an ID on it: MyView() .toolbar { ToolbarItem(id: "some-value") { ... } ToolbarItem(id: "some-other-value") { ... } ToolbarItem(id: "yet-another-value") { ... } } There's also an error regarding the contents of a Table, so you may need to look into that as well.

I just stumbled into this forum post from Mastodon, but I can at least share how I've set this up for one of my projects, Fedigardens. Fedigardens has a workspace that I use which contains the main iOS app project and all of its internal Swift packages like networking libraries and feature modules. I have a test plan file that contains the tests that I want to execute, which is tied to the main app's scheme. When I set up the testing workflow, I made sure to select the test plan I created with all the unit tests. Suffice to say, this approach seems to work well for my use cases. So, a step-by-step process: Create an Xcode workspace and iOS app project. Add the Swift packages and iOS app to that workspace. Create a test plan file (.xctestplan) by going to File > New > File... and select 'Test Plan'. In that test plan, add the Swift package tests (and any other tests) you'd like to execute. In the test section of the iOS app's scheme, add the existing test plan you created. Create an Xcode Cloud workflow as usual, targeting the test plan when adding the test action.

I've reached out to Apple via a TSI about this particular issue. As of the current release of SwiftUI, this isn't possible. They recommend I use the .sheet modifier instead and drop the split window capability. Otherwise, I can create a UISceneDelegate and use UIKit APIs directly: let options = UIWindowScene.ActivationRequestOptions() options.preferredPresentationStyle = .prominent let userActivity = NSUserActivity(activityType: SecondSceneDelegate.sceneUserActivityType) userActivity.targetContentIdentifier = SecondSceneDelegate.sceneUserActivityType UIApplication.shared.requestSceneSessionActivation(nil, userActivity: userActivity, options: options, errorHandler: nil) I do hope to see this improve in the future, though.