我使用xcodebuild从命令行构建后得到以下内容，任何想法可能出错？
** BUILD FAILED **
The following build commands failed:
CompileC build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv6/AppDelegate.o PackageDemo/AppDelegate.m normal armv6 objective-c com.apple.compilers.llvm.clang.1_0.compiler
CompileC build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv6/main.o PackageDemo/main.m normal armv6 objective-c com.apple.compilers.llvm.clang.1_0.compiler
CompileC build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv7/main.o PackageDemo/main.m normal armv7 objective-c com.apple.compilers.llvm.clang.1_0.compiler
CompileC build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv7/AppDelegate.o PackageDemo/AppDelegate.m normal armv7 objective-c com.apple.compilers.llvm.clang.1_0.compiler
Ld build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv6/PackageDemo normal armv6
Ld build/PackageDemo.build/Release-iphoneos/PackageDemo.build/Objects-normal/armv7/PackageDemo normal armv7
CreateUniversalBinary build/Release-iphoneos/PackageDemo.app/PackageDemo normal "armv6 armv7"
GenerateDSYMFile build/Release-iphoneos/PackageDemo.app.dSYM build/Release-iphoneos/PackageDemo.app/PackageDemo
（8次失败）