title: When I run flutter build IOS gets stuck in the middle of process
body: <p>Whenever I run flutter build IOS, it seems to work fine, however when it gets to the point of "Building Dart Code", it just gets stuck there forever.
  I was however been able to run flutter build apk successfully before this.</p>
  
  <p>This is the flutter doctor -v output:</p>
  
  <pre><code>[✓] Flutter (Channel beta, v0.11.3, on Mac OS X 10.13.6 17G65, locale en-GB)
      • Flutter version 0.11.3 at /Users/../flutter
      • Framework revision 72bf075e8d (4 days ago), 2018-11-09 20:36:17 -0800
      • Engine revision 5646e86a6f
      • Dart version 2.1.0 (build 2.1.0-dev.9.3 9c07fb64c4)
  
  [✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
      • Android SDK at /Users/../Library/Android/sdk
      • Android NDK location not configured (optional; useful for native profiling support)
      • Platform android-27, build-tools 27.0.3
      • Java binary at: /Library/Java/JavaVirtualMachines/jdk1.8.0_191.jdk/Contents/Home/bin/java
      • Java version Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
      • All Android licenses accepted.
  
  [✓] iOS toolchain - develop for iOS devices (Xcode 10.0)
      • Xcode at /Applications/Xcode.app/Contents/Developer
      • Xcode 10.0, Build version 10A255
      • ios-deploy 1.9.2
      • CocoaPods version 1.5.3
  
  [✓] Android Studio (version 3.2)
      • Android Studio at /Applications/Android Studio.app/Contents
      • Flutter plugin version 30.0.1
      • Dart plugin version 181.5656
      • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)
  
  [!] Android Studio
      • Android Studio at /Applications/Android/Contents
      ✗ Flutter plugin not installed; this adds Flutter specific functionality.
      ✗ Dart plugin not installed; this adds Dart specific functionality.
      ✗ Android Studio not found at /Applications/Android/Contents
      • Try updating or re-installing Android Studio.
  
  [✓] VS Code (version 1.24.1)
      • VS Code at /Applications/Visual Studio Code.app/Contents
      • Flutter extension version 2.20.0
  
  [✓] Connected device (1 available)
      • .. iPhone • 77afb908fc6c490d3fca62cdde9a74ab4e45b4f0 • ios • iOS 11.4.1
  
  ! Doctor found issues in 1 category.
  </code></pre>
  
  <p>I will also post where exactly gets stuck:</p>
  
  <p>-MacBook-Pro:flutterLoginApp-master4OK ..$ flutter build ios<br>
  Building Login for device (ios-release)...    Automatically signing iOS for device deployment using specified development team in Xcode project: ...<br>
  Starting Xcode build...                                        ├─Building Dart code... 1.6s //and just gets stuck here forever ...</p>