Hello there ^^. I have compiled GCC 4.8.2 and I am prepairing a re-distribution together with some packages. But there is something I noticed: There are no default headers installed. At least not those for Objective C. So, during compilation, I moved everything into /opt/GNUstep (because I am building it for Mac right now) by using —prefix. And now that I have compiled it, I moved /usr/include to /usr/include-apple in order to „disable“ it, since I want to test the build like it was on a non-developer unit - on which you won’t have the headers. So, this is what I get. Ingwie@ingwies-air ~/Work/objc $ which gcc /opt/GNUstep/bin//gcc Ingwie@ingwies-air ~/Work/objc $ echo $PATH /opt/GNUstep/bin/:/opt/GNUstep/usr/local/bin/:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin Ingwie@ingwies-air ~/Work/objc $ cat win.m #import <Foundation/Foundation.h> int main() { NSString *str = @"o.o"; NSLog(@"%@", str); return 0; } Ingwie@ingwies-air ~/Work/objc $ gcc win.m -o test In file included from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6:0, from win.m:1: /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:11:23: fatal error: sys/types.h: No such file or directory #include <sys/types.h> ^ compilation terminated. But … if I try to build WITH the default includes folder: Ingwie@ingwies-air ~/Work/objc $ sudo mv /usr/include-apple/ /usr/include Ingwie@ingwies-air ~/Work/objc $ gcc win.m -o test In file included from /usr/include/os/object.h:74:0, from /usr/include/dispatch/dispatch.h:48, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/objc/NSObject.h:21:26: error: expected ‘;’ before ‘OBJC_ARC_UNAVAILABLE’ - (struct _NSZone *)zone OBJC_ARC_UNAVAILABLE; ^ /usr/include/objc/NSObject.h:35:14: error: expected ‘;’ before ‘OBJC_ARC_UNAVAILABLE’ - (id)retain OBJC_ARC_UNAVAILABLE; ^ /usr/include/objc/NSObject.h:36:24: error: expected ‘;’ before ‘OBJC_ARC_UNAVAILABLE’ - (oneway void)release OBJC_ARC_UNAVAILABLE; ^ /usr/include/objc/NSObject.h:37:19: error: expected ‘;’ before ‘OBJC_ARC_UNAVAILABLE’ - (id)autorelease OBJC_ARC_UNAVAILABLE; ^ /usr/include/objc/NSObject.h:38:27: error: expected ‘;’ before ‘OBJC_ARC_UNAVAILABLE’ - (NSUInteger)retainCount OBJC_ARC_UNAVAILABLE; ^ /usr/include/objc/NSObject.h:48:1: error: unknown type name ‘OBJC_ROOT_CLASS’ OBJC_ROOT_CLASS ^ /usr/include/objc/NSObject.h:50:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘interface’ @interface NSObject <NSObject> { ^ /usr/include/objc/NSObject.h:69:63: error: expected ‘:’ before ‘;’ token + (id)copyWithZone:(struct _NSZone *)zone OBJC_ARC_UNAVAILABLE; ^ In file included from /usr/include/dispatch/dispatch.h:50:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/object.h:249:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t finalizer); ^ In file included from /usr/include/dispatch/dispatch.h:52:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/queue.h:180:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/queue.h:246:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/queue.h:651:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/queue.h:731:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/queue.h:790:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/queue.h:832:17: error: unknown type name ‘dispatch_function_t’ void *context, dispatch_function_t destructor); ^ In file included from /usr/include/dispatch/dispatch.h:53:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/source.h:405:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t handler); ^ /usr/include/dispatch/source.h:464:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t cancel_handler); ^ /usr/include/dispatch/source.h:739:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t registration_handler); ^ In file included from /usr/include/dispatch/dispatch.h:54:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/group.h:123:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ /usr/include/dispatch/group.h:233:2: error: unknown type name ‘dispatch_function_t’ dispatch_function_t work); ^ In file included from /usr/include/dispatch/dispatch.h:56:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/once.h:79:3: error: unknown type name ‘dispatch_function_t’ dispatch_function_t function); ^ /usr/include/dispatch/once.h:85:3: error: unknown type name ‘dispatch_function_t’ dispatch_function_t function) ^ In file included from /usr/include/dispatch/dispatch.h:57:0, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFStream.h:15, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CFPropertyList.h:13, from /System/Library/Frameworks/CoreFoundation.framework/Headers/CoreFoundation.h:55, from /System/Library/Frameworks/Foundation.framework/Headers/Foundation.h:6, from win.m:1: /usr/include/dispatch/data.h:85:1: error: unknown type name ‘dispatch_function_t’ DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(free); ^ /usr/include/dispatch/data.h:94:1: error: unknown type name ‘dispatch_function_t’ DISPATCH_DATA_DESTRUCTOR_TYPE_DECL(munmap); ^ Any idea what THAT is - or what is wrong with my hdeaders? Are there ways to obtain compatible headers? Kind regards - Ingwie.