title: use xcodebuild to creat a CI system, error : "Ld build xxxx normal arm64"
body: <p>Recently I was asked to creat a CI system, so I tride to use xcodebuild.<br>
  But I got Errors, the command is :<code>xcodebuild -sdk iphoneos -configuration Release clean build</code></p>
  
  <blockquote>
    <p><strong>Errors:</strong><br>
    ld: library not found for -lFMDB
    clang: error: linker command failed with exit code 1 (use -v to see invocation)</p>
    
    <p>** BUILD FAILED **</p>
    
    <p>The following build commands failed:
      Ld build/ProjectName.build/Release-iphoneos/ProjectName.build/Objects-normal/armv7/ProjectName normal armv7</p>
    
    <p>Ld build/ProjectName.build/Release-iphoneos/ProjectName.build/Objects-normal/arm64/ProjectName normal arm64  </p>
  </blockquote>
  
  <p>I import FMDB by cocoa pods, and <strong>Header Search Path</strong> has this path <code>"${PODS_ROOT}/Headers/Public/FMDB"</code>.</p>
  
  <p>Please help me,thx very much.</p>