🐛 [firebase_ml_vision][iOS] PlatformException(Error 13, com.firebase.ml, Barcode engine is nil., null)

[llullanqui]

I've been using the 'firebase_ml_vision' package to scan Qr codes in an Image Stream provided by the 'camera' package. Everything was fine until the update that happened in Nov. 6. In Android, I can still scan qr codes without problems. But in iOS, i'm having the app is throwing the Exception: PlatformException(Error 13, com.firebase.ml, Barcode engine is nil., null)

I've updated my podfile with the line pod 'GoogleMLKit/BarcodeScanning', because the command 'flutter build ios' finished with an error when the Podfile had pod 'Firebase/MLVisionBarcodeModel' instead. The pod update command explained that the package 'Firebase/MLVisionBarcodeModel' was deprecated, and thought it was the source of the problem.

Still the problem keeps happening.

Flutter doctor -v output:

[✓] Flutter (Channel stable, 1.22.4, on Mac OS X 10.15.6 19G73 darwin-x64, locale en-EC)
    • Flutter version 1.22.4 at /Applications/flutter_sdk/jaime/flutter
    • Framework revision 1aafb3a8b9 (3 weeks ago), 2020-11-13 09:59:28 -0800
    • Engine revision 2c956a31c0
    • Dart version 2.10.4

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
    • Android SDK at /Users/jvasquez/Library/Android/sdk
    • Platform android-29, build-tools 29.0.3
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.1, Build version 12A7403
    • CocoaPods version 1.10.0

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 46.0.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.51.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.16.0

[!] Connected device
    ! No devices available

! Doctor found issues in 1 category.

This is the code I use to analyze the CameraImage:

  static Future<List<Barcode>> detect({
    @required CameraImage image,
    // @required BarcodeDetector detector,
    @required int imageRotation,
  }) async {
    var rp = List<Barcode>();
    try {
      BarcodeDetector detector = FirebaseVision.instance.barcodeDetector(
        BarcodeDetectorOptions(
          barcodeFormats: BarcodeFormat.qrCode,
        )
      );
      var metadata = _buildMetaData(image, _rotationIntToImageRotation(imageRotation));
      FirebaseVisionImage visionImage = FirebaseVisionImage.fromBytes(_concatenatePlanes(image.planes), metadata);
      rp = await detector.detectInImage(visionImage);
    } catch (ex) {
      print("Ocurrió un error: $ex");
      // UtilFunctions.escribirEnLog(
      //   mensaje: "$ex",
      //   nombreFuncion: "detect",
      //   tipo: 0,
      // );
    }
    
    return rp;
  }

  static Uint8List _concatenatePlanes(List<Plane> planes) {
    final WriteBuffer allBytes = WriteBuffer();
    for (Plane plane in planes) {
      allBytes.putUint8List(plane.bytes);
    }
    return allBytes.done().buffer.asUint8List();
  }

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__))
end

# post_install do |installer|
#   installer.pods_project.targets.each do |target|
#     flutter_additional_ios_build_settings(target)
#   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'] = '12.0'
    end
  end
end

# pod 'Firebase/MLVisionBarcodeModel'
pod 'GoogleMLKit/BarcodeScanning'

flutter build ios error when having pod 'Firebase/MLVisionBarcodeModel' in the Podfile (Was too long to post):
File

[markusaksli-nc]

Hi @llullanqui
This could be because of the different MLKit you are using. The deprecation message might be correct but I'm not sure the plugin supports the new kit yet.

What was the error you ran into before? I'm having no issues building for iOS on the latest master 1.25.0-5.0.pre.45 with firebase_ml_vision: ^0.9.9 and pod 'Firebase/MLVisionBarcodeModel'.

flutter doctor -v

[✓] Flutter (Channel master, 1.25.0-5.0.pre.45, on macOS 11.0.1 20B29 darwin-x64, locale en-GB)
    • Flutter version 1.25.0-5.0.pre.45 at /Users/markus/development/flutter_master
    • Framework revision 81e1f7d1ed (6 hours ago), 2020-12-02 17:19:57 -0800
    • Engine revision 20caf54969
    • Dart version 2.12.0 (build 2.12.0-76.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at /Users/markus/Library/Android/sdk
    • Platform android-30, build-tools 30.0.1
    • Java binary at: /Users/markus/Library/Application Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/201.6953283/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.2)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.2, Build version 12B45b
    • CocoaPods version 1.10.0

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • Android Studio at /Users/markus/Library/Application Support/JetBrains/Toolbox/apps/AndroidStudio/ch-0/201.6953283/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      � https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      � https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] Connected device (4 available)
    • Nevercode’s iPhone (mobile) • b668e524315069f3db3661ac11ff1f66afafebdb • ios            • iOS 14.2
    • macOS (desktop)             • macos                                    • darwin-x64     • macOS 11.0.1 20B29 darwin-x64
    • Web Server (web)            • web-server                               • web-javascript • Flutter Tools
    • Chrome (web)                • chrome                                   • web-javascript • Google Chrome 87.0.4280.67

• No issues found!

[llullanqui]

For some reason, putting the pod pod 'Firebase/MLVisionBarcodeModel' made the command flutter build ios finish with an error. Putting the line inside the target 'Runner' do worked for me.

New 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
  pod 'Firebase/MLVisionBarcodeModel'
  use_frameworks!
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

# post_install do |installer|
#   installer.pods_project.targets.each do |target|
#     flutter_additional_ios_build_settings(target)
#   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'] = '12.0'
    end
  end
end

# pod 'Firebase/MLVisionBarcodeModel'
# pod 'GoogleMLKit/BarcodeScanning'

Maybe the documentation in the flutter Firebase_ml_vision plugin page needs an update because the iOS section isn't very clear on where to put the line.

[markusaksli-nc]

Strange, it works for me just adding it to the end of the file.

Just to confirm, everything is working fine now?

[llullanqui]

Yes, writing the line in the Podfile, to use the In-App api, made it work fine. I can detect qr codes now.

[markusaksli-nc]

Thank you, closing this as solved.