Flutter Project Build Issue

[masterAI359]

---

🧩 Problem Description

I am attempting to build a project written with Flutter 3.35 (stable) for iOS 18, and run it using the iOS Simulator.

The Xcode build completes successfully, but the subsequent simulator build fails with the following error:

Failed to build iOS app
Parse Issue (Xcode): Module 'cloud_firestore' not found
/Users/mwp/Documents/wellness/ios/Runner/GeneratedPluginRegistrant.m:11:8

Could not build the application for the simulator.
Error launching application on Emulator.

---

📁 Environment

• Flutter version: 3.35.0 (stable)
• Dart version: 3.10.0
• Xcode version: 9.3
• CocoaPods version: 1.15.2
• iOS version (simulator): 18.0
• Device: iPhone 16 Pro Simulator

---

📜 Podfile

# Uncomment this line to define a global platform for your project
platform :ios, '16.0'

# 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)
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '16.0'
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= [
        '$(inherited)',
        'PERMISSION_CAMERA=1',
        'PERMISSION_PHOTOS=1',
        'PERMISSION_MICROPHONE=1',
        'PERMISSION_NOTIFICATIONS=1',
      ]
    end
  end
end

---

🧠 What I’ve Tried

• Ran pod deintegrate && pod install inside the ios/ directory

• Cleaned the Flutter build:

  flutter clean
  flutter pub get
  

• Rebuilt pods using:

  pod repo update
  pod install
  

• Verified that cloud_firestore is correctly declared in pubspec.yaml

---

🆘 Question

Could you please help identify:

1. The cause of this “Module ‘cloud_firestore’ not found” error during simulator build, and
2. The recommended steps to resolve it when targeting iOS 18 with Flutter 3.35.

---

📸 Screenshots

---

[mhashir03]

Short version: your toolchain is mismatched. You’re trying to run an iOS 18 simulator with Xcode 9.3—that can’t work. The “Module ‘cloud_firestore’ not found” is a side-effect of the wrong SDK/Pods build, not the real root cause.

Fix (do these in order)

Upgrade Xcode

Install Xcode 16.x (required for iOS 18 simulators).

xcode-select --switch /Applications/Xcode.app

Open Xcode once → accept license → install iOS 18 simulators.

Clean CocoaPods/Flutter artifacts

rm -rf ios/Pods ios/Podfile.lock ios/Runner.xcworkspace
flutter clean
flutter pub get
cd ios
pod repo update
pod install

Simplify your Podfile

Remove use_modular_headers! (it often breaks Firebase imports).

Prefer static frameworks (Firebase-friendly):

target 'Runner' do
use_frameworks! :linkage => :static
flutter_install_all_ios_pods File.dirname(File.realpath(FILE))
target 'RunnerTests' do
inherit! :search_paths
end
end

Keep your platform :ios, '16.0' and your post_install block.

Open the correct workspace & build for simulator

Open ios/Runner.xcworkspace (not the .xcodeproj).

Select an iOS 18 simulator (e.g., iPhone 16 Pro) and build.

If you hit arch errors on Apple Silicon (only if needed)
Add in post_install:

config.build_settings['EXCLUDED_ARCHS[sdk=iphonesimulator*]'] = 'arm64'

Then pod install again.

Verify package versions

Make sure cloud_firestore is up to date and compatible with Flutter 3.35:

flutter pub outdated cloud_firestore

If you use Firebase, ensure your iOS setup is complete (GoogleService-Info.plist present, flutterfire configure if applicable).

[masterAI359]

Thank you so much.
Following the method you provided solved the problem.

[masterAI359]

Thank you for your assistance.
The project was built successfully and tested on the Simulator; however, when I connected my iPhone to my Mac for Firebase Messaging function testing, Xcode did not find the device. Interestingly, the Mac’s screen mirroring feature still detects the phone.
Additionally, running flutter devices does not list the iPhone either.
I would appreciate any insights into what might be causing this issue and suggestions on how to resolve it.
Thank you for your continued support. 🙇
This is a screenshot