Flutter Firebase Exception: Error running pod install

Question

I'm experiencing an issue with my Flutter project that I've created. I've set up the Firebase connections correctly, and the project works fine on Android. However, it's not working on iOS, and I'm getting a pod installation error. I've tried everything I found on the internet, but it's still not working.

Here is my pubspec.yaml:

name: istanbul_towel_application
description: A new Flutter project.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev.

version: 1.0.0+1

environment:
  sdk: '>=3.0.1 <4.0.0'

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.2
  firebase_core: ^2.7.0
  firebase_auth: ^4.2.9
  image_picker: ^0.8.7
  cloud_firestore: ^4.12.1
  firebase_storage: ^11.4.0

dev_dependencies:
  flutter_test:
    sdk: flutter
  flutter_lints: ^2.0.0

flutter:
  uses-material-design: true
  assets:
    - assets/istanbul_towel_logo.png

and my podfile:

# Uncomment this line to define a global platform for your project
platform :ios, '12.0'

# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
ENV['COCOAPODS_DISABLE_STATS'] = 'true'

project 'Runner', {
  'Debug' => :debug,
  'Profile' => :release,
  'Release' => :release,
}

def flutter_root
  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
  unless File.exist?(generated_xcode_build_settings_path)
    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
  end

  File.foreach(generated_xcode_build_settings_path) do |line|
    matches = line.match(/FLUTTER_ROOT\=(.*)/)
    return matches[1].strip if matches
  end
  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
end

require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)

flutter_ios_podfile_setup

target 'Runner' do
  use_frameworks!
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
  target 'RunnerTests' do
    inherit! :search_paths
  end
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
  end
end

and my podfile.lock:

platform :ios, '12.0'

ENV['COCOAPODS_DISABLE_STATS'] = 'true'

project 'Runner', {
  'Debug' => :debug,
  'Profile' => :release,
  'Release' => :release,
}

def flutter_root
  # ...
  # (More code here)
  # ...
end

require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)

flutter_ios_podfile_setup

target 'Runner' do
  use_frameworks!
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
  target 'RunnerTests' do
    inherit! :search_paths
  end
end

post_install do |installer|
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
  end
end

Execute pod update

Execute pod install (it can take a some minutes to download dependencies)

Execute flutter run

cd ios
rm Podfile.lock
pod repo update