Xcode 5.1: library not found for -lz.1.2.3

Question

This is a bugger and it's been frustrating me for some time.

I get this output when building my Xcode project:

ld: library not found for -lz.1.2.3 clang: error: linker command failed with exit code 1 (use -v to see invocation)

The entire output:

Ld /Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Products/Debug-iphonesimulator/LROAuth2Demo.app/LROAuth2Demo normal i386
    cd /Users/Yashwant/Downloads/OAuth/LROAuth2Demo
    export IPHONEOS_DEPLOYMENT_TARGET=7.1
    export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.1.sdk -L/Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Products/Debug-iphonesimulator -F/Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Products/Debug-iphonesimulator -filelist /Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Intermediates/LROAuth2Demo.build/Debug-iphonesimulator/LROAuth2Demo.build/Objects-normal/i386/LROAuth2Demo.LinkFileList -Xlinker -objc_abi_version -Xlinker 2 -fobjc-link-runtime -Xlinker -no_implicit_dylibs -mios-simulator-version-min=7.1 -framework Foundation -framework UIKit -framework CoreGraphics -framework SystemConfiguration -framework CFNetwork -lz.1.2.3 -framework MobileCoreServices -Xlinker -dependency_info -Xlinker /Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Intermediates/LROAuth2Demo.build/Debug-iphonesimulator/LROAuth2Demo.build/Objects-normal/i386/LROAuth2Demo_dependency_info.dat -o /Users/Yashwant/Library/Developer/Xcode/DerivedData/LROAuth2Demo-eviojihhpjtuqxfkfctmczczudhr/Build/Products/Debug-iphonesimulator/LROAuth2Demo.app/LROAuth2Demo

I have had few "linker command" failures before, but they seem to be fixed by simply cleaning the project and re-building. In this case, I was pointed out that I had to install the command line developer tools for Xcode 5, but unfortunately the error still doesn't go away.

For complete assurance I checked if I had actually installed them by using pkgutil --pkg-info=com.apple.pkg.CLTools_Executables and it returns:

package-id: com.apple.pkg.CLTools_Executables version: 5.1.0.0.1.1393561416 volume: / location: / install-time: 1396984437 groups: com.apple.FindSystemFiles.pkg-group com.apple.DevToolsBoth.pkg-group com.apple.DevToolsNonRelocatableShared.pkg-group

So I restarted my computer, but still no results.

Answer 1

The problem as @photoionized pointed out was partly due to the version of zlib or libz. Because the project was old it was using libz.1.2.3 instead of the latest libz.1.2.5. So to update that, I found this question.

Basically I had to delete the old one and replace it with the new one.

Link against the libz.dylib, but add it through the Build Phases tab.

Project >> Target >> Build Phases >> Link Binary With Libraries

Press + under the list and select the libz.dylib then it will add the lib so it will work inbetween SDK updates.