I have tried to build the app manually on the command line, now using clang instead of gcc and -arch i386 instead of -m32
cd /Build/Test; \
/Library/GNUstep/Makefiles/mkinstalldirs ./obj/Test.obj/
/Library/GNUstep/Makefiles/mkinstalldirs /Build/Test/Test.app/Contents/MacOS
cd /Users/ahoesch/Development/Test
clang Controller.m -c \
-MMD -MP -DNeXT_Foundation_LIBRARY=1 -DNeXT_GUI_LIBRARY=1 -DNeXT_RUNTIME=1 -fno-strict-aliasing -fexceptions -fobjc-exceptions -D_NATIVE_OBJC_EXCEPTIONS -fobjc-nonfragile-abi -D_NONFRAGILE_ABI -pthread -dynamic -fno-common -Wall -DGSWARN -DGSDIAGNOSE -Wno-import -g -O2 -fnext-runtime -arch i386 -Wno-parentheses -Wno-import -I. -I/usr/local/include/ -F/Library/Frameworks/ \
-o /Build/Test/obj/Test.obj/Controller.m.o
clang main.m -c \
-MMD -MP -DNeXT_Foundation_LIBRARY=1 -DNeXT_GUI_LIBRARY=1 -DNeXT_RUNTIME=1 -fno-strict-aliasing -fexceptions -fobjc-exceptions -D_NATIVE_OBJC_EXCEPTIONS -fobjc-nonfragile-abi -D_NONFRAGILE_ABI -pthread -dynamic -fno-common -Wall -DGSWARN -DGSDIAGNOSE -Wno-import -g -O2 -fnext-runtime -arch i386 -Wno-parentheses -Wno-import -I. -I/usr/local/include/ -F/Library/Frameworks/ \
-o /Build/Test/obj/Test.obj/main.m.o
clang -arch i386 -shared-libgcc -pthread -fexceptions -fnext-runtime -o /Build/Test/Test.app/Contents/MacOS/Test \
/Build/Test/obj/Test.obj/Controller.m.o /Build/Test/obj/Test.obj/main.m.o -F/Library/Frameworks/ -framework AppKit -framework Foundation -lobjc -lm
admins-iMac:Test ahoesch$ clang -arch i386 -shared-libgcc -pthread -fexceptions -fnext-runtime -o /Build/Test/Test.app/Contents/MacOS/Test /Build/Test/obj/Test.obj/Controller.m.o /Build/Test/obj/Test.obj/main.m.o -F/Library/Frameworks/ -framework AppKit -framework Foundation -lobjc -lm
clang: warning: argument unused during compilation: '-pthread' [-Wunused-command-line-argument]
Undefined symbols for architecture i386:
"_OBJC_CLASS_$_NSApplication", referenced from:
objc-class-ref in main.m.o
"_OBJC_CLASS_$_NSAutoreleasePool", referenced from:
objc-class-ref in main.m.o
"_OBJC_CLASS_$_NSImage", referenced from:
objc-class-ref in main.m.o
"_OBJC_CLASS_$_NSObject", referenced from:
_OBJC_CLASS_$_Controller in Controller.m.o
"_OBJC_CLASS_$_NSProcessInfo", referenced from:
objc-class-ref in main.m.o
"_OBJC_CLASS_$_NSString", referenced from:
objc-class-ref in main.m.o
"_OBJC_METACLASS_$_NSObject", referenced from:
_OBJC_METACLASS_$_Controller in Controller.m.o
"_objc_msgSendSuper2", referenced from:
-[Controller dealloc] in Controller.m.o
ld: symbol(s) not found for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)