Reference to var 'FlutterMethodNotImplemented' is not concurrency-safe because it involves shared mutable state

Question

I am using SwiftFlutterJailbreakDetectionPlugin and while I am calling method result() and passing FlutterMethodNotImplemented in then I am getting error Reference to var 'FlutterMethodNotImplemented' is not concurrency-safe because it involves shared mutable state

import Flutter
import UIKit
import IOSSecuritySuite
public class SwiftFlutterJailbreakDetectionPlugin: NSObject, FlutterPlugin {
  public static func register(with registrar: FlutterPluginRegistrar) {
    let channel = FlutterMethodChannel(name: "flutter_jailbreak_detection", binaryMessenger: registrar.messenger())
    let instance = SwiftFlutterJailbreakDetectionPlugin()
    registrar.addMethodCallDelegate(instance, channel: channel)
  }

  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
        switch call.method {
        case "jailbroken":
            
            let check2 = IOSSecuritySuite.amIJailbroken()
            result(check2)
            break
        case "developerMode":
            result(IOSSecuritySuite.amIRunInEmulator())
            break
        default:
            result(FlutterMethodNotImplemented)
        }
  }
}

Answer 1

Use Preconcurrency Conformance. This is a new feature of Swift 6. The whole idea with this one is to provide a simple and safe way to deal with protocol-isolation mismatches. It tells the compiler yes, actually, my isolated type can conform to this non-isolated protocol.

use @preconcurrency before the import Flutter as shown below

@preconcurrency import Flutter 

Note: in my case, it worked.