title: codesign_allocate: error: unable to find utility "codesign_allocate", not a developer tool or in PATH
body: <p>I upgraded my Mac to 10.10.3 and Xcode to 6.3.1 yesterday; today I can't use git, <code>codesign_allocate</code>....and more.</p>
  
  <pre><code>`sh: line 1: 18421 Abort trap: 6           /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild -sdk /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.3.sdk -find codesign_allocate 2&gt; /dev/null
  codesign_allocate: error: unable to find utility "codesign_allocate", not a developer tool or in PATH
  /Users/ylx/Library/Developer/Xcode/DerivedData/test-ahpvhmtqeafuveekexklyxulvmfa/Build/Products/Debug-iphoneos/test.app/Frameworks/libswiftCore.dylib: the codesign_allocate helper tool cannot be found or used
  *** error: Couldn't codesign /Users/ylx/Library/Developer/Xcode/DerivedData/test-ahpvhmtqeafuveekexklyxulvmfa/Build/Products/Debug-iphoneos/test.app/Frameworks/libswiftCore.dylib: codesign failed with exit code 1
  Command /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-stdlib-tool failed with exit code 1`
  </code></pre>