defer inside Task modifier in Swift

Question

How can I call defer inside the Task modifier in Swift? I want to perform clean up operations in defer. This includes setting loadingState to .idle and selectedImage to nil etc. The defer code should fire whether the exception is thrown or not.

Task {
    do {
        defer {
            print("DEFER")
            self.selectedImage = nil
            loadingState = .idle
            chatText = ""
        }
            
        try await sendMessage()
        print("")
    } catch {
        print(error.localizedDescription)
    }
}

But I get the following compilation error:

Main actor-isolated property 'loadingState' can not be mutated from the main actor

Any help is appreciated.

UPDATE:

Task { @MainActor in
    
    do {
        
        defer {
            print("DEFER")
            loadingState = .idle
            self.selectedImage = nil
            loadingState = .idle
            chatText = ""
        }
        
        try await sendMessage()
        
    } catch {
        print(error.localizedDescription)
    }
    
}

UPDATE 2

Here is minimal code that produces a similar error:

enum SampleError: Error {
    case operationFailed
}

func doSomething() {
    
    var age = 40
    
    Task {
        do {
            
            defer {
               age = 50
            }
            
            throw SampleError.operationFailed
        } catch {
            print(error)
        }
            
    }
}

doSomething()

Answer 1

This was a known bug that has since been fixed in the Swift compiler. It is resolved in Swift 5.8+ via this patch to the Swift compiler.

This enables the following (simplified) code example to compile correctly.

// Compiles on Swift 5.8+
@MainActor
class Tester {
    var x = 0
    
    func run() {
        Task {
            defer { x += 1 }
        }
    }   
}