title: Flutter iOS build failing on BigSur, XCode 12
body: <p>Flutter iOS build fails due to issues with headers.</p>
  <p>I followed the simple steps mentioned on flutter.dev for launching an app on iOS simulator. I've had no problems working with flutter on Android/Web, but this is the first time I've tried running it on iOS.</p>
  <p>Summary of error - (Complete Error: <a href="https://gist.github.com/mannprerak2/520f8a749431a50b8472783c71d67dda" rel="nofollow noreferrer">https://gist.github.com/mannprerak2/520f8a749431a50b8472783c71d67dda</a>)</p>
  <pre><code>...
     #import &quot;Headers/CoreMedia.h&quot;
              ^
      /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.4.sdk/System/Library/Frameworks/CoreMedia.framework/Headers/CoreMedia.h:15:10: note: in file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.4.sdk/System/Library/Frameworks/CoreMedia.framework/Headers/CoreMedia.h:15:
      #include &lt;CoreMedia/CMFormatDescription.h&gt;
               ^
      /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator14.4.sdk/System/Library/Frameworks/CoreMedia.framework/Headers/CMFormatDescription.h:26:10: error: could not build module 'CoreAudio'
      #include &lt;CoreAudio/CoreAudioTypes.h&gt;
               ^
      /Users/prerakmann/development/test_ios/ios/Runner/Runner-Bridging-Header.h:1:9: note: in file included from /Users/prerakmann/development/test_ios/ios/Runner/Runner-Bridging-Header.h:1:
      #import &quot;GeneratedPluginRegistrant.h&quot;
              ^
      /Users/prerakmann/development/test_ios/ios/Runner/GeneratedPluginRegistrant.h:8:9: error: could not build module 'Flutter'
      #import &lt;Flutter/Flutter.h&gt;
              ^
      192 errors generated.
      &lt;unknown&gt;:0: error: failed to emit precompiled header '/Users/prerakmann/Library/Developer/Xcode/DerivedData/Runner-ahrcvwuwhqnepxdcpfsagztcuwrr/Build/Intermediates.noindex/PrecompiledHeaders/Runner-Bridging-Header-swift_1QEOMJ6SUMBGB-clang_3BG5Q8JCTPBV5.pch' for bridging header '/Users/prerakmann/development/test_ios/ios/Runner/Runner-Bridging-Header.h'
      384 errors generated.
      &lt;unknown&gt;:0: error: generate-pch command failed with exit code 1 (use -v to see invocation)
      note: Using new build system
      note: Building targets in parallel
      note: Planning build
      note: Constructing build description
  ...
  </code></pre>
  <p>System: Macbook Pro 13 (2020), BigSur 11.2.1, Xcode 12.4</p>
  <p>Flutter: Tried on the latest stable and beta channel.</p>
  <p>Simulator: Tried on iOS 8, iOS 12.</p>
  <p>Steps to reproduce: Create a new flutter app, run it.</p>