title: IOS: Library not found for -lz.1.2.3
body: <p>I don't understand my error:</p>
  <blockquote>
  <p>Ld
  Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/Test.app/Test
  normal i386</p>
  <pre><code>cd /Users/lol/Desktop/Test
  
  setenv MACOSX_DEPLOYMENT_TARGET 10.6
  
  setenv PATH &quot;/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin&quot;
  
  /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-gcc-4.2
  </code></pre>
  <p>-arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk</p>
  <p>-L/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator</p>
  <p>-L/Users/lol/Desktop/Test -F/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator</p>
  <p>-filelist /Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Intermediates/Test.build/Debug-iphonesimulator/Test.build/Objects-normal/i386/Test.LinkFileList</p>
  <p>-mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -ObjC -D__IPHONE_OS_VERSION_MIN_REQUIRED=40000 -lextThree20JSON+SBJSON /Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20UICommon.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20UINavigator.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20Core.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20UI.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20Network.a</p>
  <p>/Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/libThree20Style.a</p>
  <p>-framework SystemConfiguration -framework MobileCoreServices -framework CFNetwork -framework AddressBook -framework AddressBookUI -framework QuartzCore -framework UIKit -framework Foundation -framework MessageUI -framework CoreGraphics -lz.1.2.3 -lxml2.2.7.3 -o /Users/lol/Library/Developer/Xcode/DerivedData/Test-aywxyvnakaqhmwfbwellynwqmoik/Build/Products/Debug-iphonesimulator/Test.app/Test</p>
  </blockquote>
  <pre><code>ld: library not found for -lz.1.2.3
  Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-gcc-4.2 failed with exit code 1
  </code></pre>
  <p>Can you help me to understand this?</p>
  <p>Thanks a lot ;)</p>