title: How do you include SSZipArchive for IOS 5?
body: <p>For the project I'm working on I needed to unzip certain files. For this, I found the library <a href="https://github.com/samsoffes/ssziparchive" rel="nofollow noreferrer">SSZipArchive</a>. I included this in Xcode 4.2 (Right-click on the Classes folder->Add files to project, with in the dialogue the "Copy items into destination group's folder"-checkbox checked). I include the libz library (I've tried both libz and zlib1.2.5). I try to compile and suddenly I've got 20 errors:</p>
  
  <pre><code>/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:311:1: error: expected identifier or '(' [1]
   @class NSString, Protocol;
   ^    
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:313:19: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT NSString *NSStringFromSelector(SEL aSelector);
                     ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:314:44: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT SEL NSSelectorFromString(NSString *aSelectorName);
                                              ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:316:19: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT NSString *NSStringFromClass(Class aClass);
                     ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:317:43: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT Class NSClassFromString(NSString *aClassName);
                                             ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:319:19: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT NSString *NSStringFromProtocol(Protocol *proto) NS_AVAILABLE(10_5, 2_0);
                     ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:319:50: error: unknown type name 'Protocol' [1]
   FOUNDATION_EXPORT NSString *NSStringFromProtocol(Protocol *proto) NS_AVAILABLE(10_5, 2_0);
                                                    ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:320:19: error: unknown type name 'Protocol' [1]
   FOUNDATION_EXPORT Protocol *NSProtocolFromString(NSString *namestr) NS_AVAILABLE(10_5, 2_0);
                     ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:320:50: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT Protocol *NSProtocolFromString(NSString *namestr) NS_AVAILABLE(10_5, 2_0);
                                                    ^
   /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:324:30: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT void NSLog(NSString *format, ...) NS_FORMAT_FUNCTION(1,2);
                                ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:324:53:{324:53-324:76}: error: format argument not an NSString [3]
   FOUNDATION_EXPORT void NSLog(NSString *format, ...) NS_FORMAT_FUNCTION(1,2);
                                                       ^~~~~~~~~~~~~~~~~~~~~~~
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:85:49: note: instantiated from:
           #define NS_FORMAT_FUNCTION(F,A) __attribute__((format(__NSString__, F, A)))
                                                          ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:325:31: error: unknown type name 'NSString' [1]
   FOUNDATION_EXPORT void NSLogv(NSString *format, va_list args) NS_FORMAT_FUNCTION(1,0);
                                 ^
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:325:63:{325:63-325:86}: error: format argument not an NSString [3]
   FOUNDATION_EXPORT void NSLogv(NSString *format, va_list args) NS_FORMAT_FUNCTION(1,0);
                                                                 ^~~~~~~~~~~~~~~~~~~~~~~
  /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObjCRuntime.h:85:49: note: instantiated from:
           #define NS_FORMAT_FUNCTION(F,A) __attribute__((format(__NSString__, F, A)))
  </code></pre>
  
  <p>These are all errors in the core library, so probably something went wrong with including the library in Xcode. I managed to narrow down the culprit to the minizip library that SSZipArchive uses (if I remove that library, the errors disappear and the compiler runs like it should), but I'm pretty stumped on why this causes the compiler to have so many issues.</p>