Swift 2, warning: could not load any Objective-C class information from the dyld shared cache

I have found a few questions regarding this issue, yet none of them were helping with my problem. I am trying to save an object to core data using this code (which worked perfectly fine in Xcode 6 and Simulator...):

let fetchRequest = NSFetchRequest(entityName: "Patient")
let fetchedResults : [NSManagedObject]!
do {
    fetchedResults = try managedContext.executeFetchRequest(fetchRequest) as! [NSManagedObject]
    patienten = fetchedResults
}    catch {
    print("error")
}

I added the do-try-catch once I started working on this project in the Xcode 7 beta and a physical device. Now, when I hit the Save button, this piece of code is called, the app freezes and I get the following:

warning: could not load any Objective-C class information from the dyld shared cache. This will significantly reduce the quality of type information available.

Does anybody know where I went wrong?

Solution 1:

For anyone coming across this in the future, I just ran into this problem myself and it turned out that I was actually getting a stack overflow from a recursive function.

Apparently calling setValue:forKey: on an NSObject calls the respective set[Key] function, where [Key] is the (capitalized) name you gave to the forKey section.

So, if like me, you have code that looks like the following, it will cause an infinite loop and crash.

func setName(name: String) {
    self.setValue(name, forKey: "name")
}

Solution 2:

Choose Product > Clean

I had similar issue. I deleted the app from the device. Then "Product->Clean" in the XCode menu. When I ran the app again, the issue got resolved.