try 使用Xcode编译时，我收到以下错误:
**Ld /Users/doronkatz/Library/Developer/Xcode/DerivedData/iKosher-bphnihrngmqtkqfgievrrumzmyce/Build/Products/Debug-iphonesimulator/iKosher.app/iKosher normal i386
cd /Users/doronkatz/Sites/xCode/iKosher
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Xcode4/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Xcode4/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Xcode4/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 -arch i386 -isysroot /Xcode4/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.sdk -L/Users/doronkatz/Library/Developer/Xcode/DerivedData/iKosher-bphnihrngmqtkqfgievrrumzmyce/Build/Products/Debug-iphonesimulator -L/Users/doronkatz/Sites/xCode/iKosher -F/Users/doronkatz/Library/Developer/Xcode/DerivedData/iKosher-bphnihrngmqtkqfgievrrumzmyce/Build/Products/Debug-iphonesimulator -filelist /Users/doronkatz/Library/Developer/Xcode/DerivedData/iKosher-bphnihrngmqtkqfgievrrumzmyce/Build/Intermediates/iKosher.build/Debug-iphonesimulator/iKosher.build/Objects-normal/i386/iKosher.LinkFileList -mmacosx-version-min=10.6 -all_load -ObjC -Xlinker -objc_abi_version -Xlinker 2 -lz -framework Security -framework CFNetwork -framework CoreData -framework Foundation -framework UIKit -framework CoreGraphics -framework QuartzCore -o /Users/doronkatz/Library/Developer/Xcode/DerivedData/iKosher-bphnihrngmqtkqfgievrrumzmyce/Build/Products/Debug-iphonesimulator/iKosher.app/iKosher
Undefined symbols for architecture i386:
"_UTTypeCreatePreferredIdentifierForTag", referenced from:
+[ASIHTTPRequest mimeTypeForFileAtPath:] in ASIHTTPRequest.o
"_UTTypeCopyPreferredTagWithClass", referenced from:
+[ASIHTTPRequest mimeTypeForFileAtPath:] in ASIHTTPRequest.o
"_kUTTagClassMIMEType", referenced from:
+[ASIHTTPRequest mimeTypeForFileAtPath:] in ASIHTTPRequest.o
"_kUTTagClassFilenameExtension", referenced from:
+[ASIHTTPRequest mimeTypeForFileAtPath:] in ASIHTTPRequest.o
"_SCNetworkReachabilitySetCallback", referenced from:
-[Reachability startNotifier] in Reachability.o
"_SCNetworkReachabilityScheduleWithRunLoop", referenced from:
-[Reachability startNotifier] in Reachability.o
"_SCNetworkReachabilityUnscheduleFromRunLoop", referenced from:
-[Reachability stopNotifier] in Reachability.o
"_SCNetworkReachabilityCreateWithName", referenced from:
+[Reachability reachabilityWithHostName:] in Reachability.o
"_SCNetworkReachabilityCreateWithAddress", referenced from:
+[Reachability reachabilityWithAddress:] in Reachability.o
"_SCNetworkReachabilityGetFlags", referenced from:
-[Reachability currentReachabilityStatus] in Reachability.o
-[Reachability isReachable] in Reachability.o
-[Reachability isConnectionRequired] in Reachability.o
-[Reachability isConnectionOnDemand] in Reachability.o
-[Reachability isInterventionRequired] in Reachability.o
-[Reachability isReachableViaWWAN] in Reachability.o
-[Reachability isReachableViaWiFi] in Reachability.o
...
ld: symbol(s) not found for architecture i386
collect2: ld returned 1 exit status**
不知道这是什么意思.