[Flutter] Flutter on iOS: redefinition of module 'Firebase'

I've been trying to build my flutter app on iOS but flutter run is throwing the following error:

/Users/<MyUser>/Desktop/projects/app/ios/Pods/Firebase/CoreOnly/Source
s/module.modulemap:1:8: error: redefinition of module 'Firebase'
module Firebase {
^
/Users/<MyUser>/Library/Developer/Xcode/DerivedData/Runner-dbkgurnsasbvieahfnk
dontejqss/SourcePackages/checkouts/firebase-ios-sdk/CoreOnly/Sources/module.
modulemap:1:8: note: previously defined here
module Firebase {


I've imported the firebase-ios-sdk as per the instructions here. The imported modules are FirebaseCore, FirebaseAuth and FirebaseMessaging. I have not made any modifications to iOS-specific code (anything under /ios) apart from importing Firebase in the AppDelegate.swift file. The updated file now contains the following code:

import UIKit
import Flutter
import Firebase

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
FirebaseApp.configure()
GeneratedPluginRegistrant.register(with: self)
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}


After searching the error I've tried the following steps:

• flutter clean
• pod deintegrate and pod install
• Cleaning DerivedData (both through XCode and manually)
• Remove and re-add firebase-ios-sdk

But to no avail.

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