title: After update to Xcode 6 : Undefined symbols for architecture armv7: "___gnu_f2h_ieee"
body: <p>I have been trying to find the problem for hours with no result.
  I have updated to Xcode 6 and get this error on both ioS8.0 &amp; 7.1 since then :</p>
  
  <pre><code>Undefined symbols for architecture armv7:
    "___gnu_f2h_ieee", referenced from:
        _playbackCallback in Audio.o
  ld: symbol(s) not found for architecture armv7
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>Thanks for your help.</p>
  
  <p>EDIT (full build log error) :</p>
  
  <pre><code>Ld /Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Products/Debug-iphoneos/Acc.app/Acc normal armv7
  cd /Users/rjc/Desktop/apps/Acc
  export IPHONEOS_DEPLOYMENT_TARGET=7.1
  export PATH="/Applications/Xcode6-Beta2.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Applications/Xcode6-Beta2.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
  /Applications/Xcode6-Beta2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch armv7 -isysroot /Applications/Xcode6-Beta2.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.0.sdk -L/Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Products/Debug-iphoneos -L/Users/rjc/Desktop/apps/Acc/Acc -F/Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Products/Debug-iphoneos -F/Users/rjc/Desktop/apps/Acc -filelist /Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Intermediates/Acc.build/Debug-iphoneos/Acc.build/Objects-normal/armv7/Acc.LinkFileList -dead_strip -ObjC -all_load -fobjc-arc -fobjc-link-runtime -miphoneos-version-min=7.1 -lCorePlot-CocoaTouch -framework CoreTelephony -framework MediaPlayer -framework MessageUI -framework Social -framework Accelerate -framework CoreLocation -framework MobileCoreServices -framework AVFoundation -framework AudioToolbox -framework CoreAudio -framework QuartzCore -framework UIKit -framework Foundation -framework CoreGraphics -framework CoreData -Xlinker -dependency_info -Xlinker /Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Intermediates/Acc.build/Debug-iphoneos/Acc.build/Objects-normal/armv7/Acc_dependency_info.dat -o /Users/rjc/Library/Developer/Xcode/DerivedData/Acc-hjhfomxkmwbyxwbfzjbduabbhlcc/Build/Products/Debug-iphoneos/Acc.app/Acc
  </code></pre>