SwiftUI 预览 Canvas 崩溃与核心数据

Question

This might be an extremely dumb question, so sorry in advance.

I'm playing with core data and SwiftUI and I'm tryna make a simple app to store notes, but I can't seem to get the previews working. The app runs fine on the simulator but crashes on the preview canvas. I've read a lot of Reddit and StackOverflow questions but none of them is related to my problem.

I'm already passing the context variable to my views, and I'm 100% sure it's not caused because of that because the crash reports say Persistent store migration failed, missing mapping model .I know it says it requires a migration, but I didn't change any data model (it's a completely new project), and the app works completely fine on the simulator so I'm not sure if that's really the cause of the crash.

All I can think of is that SwiftUI's preview canvas may share the same database with other projects and it's conflicting (which kinda makes sense since I've got other projects that also use core data, are also made in SwiftUI, and share the name of some entities).

I had these same problems using Realm and I solved them by removing the Realm database file when using the preview canvas so every run would empty the database, and I didn't have any issue. Is this a good approach? Should I do this?

I'd show my code but it's really just a ForEach that iterates through an entity called Note .

Answer 1

Try to delete the preview canvas from here

~/Library/Developer/Xcode/UserData/Previews/Simulator Devices/

then in command line run the following

killall -9 com.apple.CoreSimulator.CoreSimulatorService

finally restart xCode

Answer 2

If you have used a simulator you will also need to delete the model's store at /Users/YOURNAME/Library/Application Support