GNUStep Undefined reference-Collection of common programming errors

I am making a program in GNUStep on windows with the following code:

#import 
#import 

int main(int argc, char *argv[]) {
    NSApplication *myApplication = [NSApplication sharedApplication];
}

However, when I compile (with gcc -o hello hello.m -I /GNUstep/System/Library/Headers -L /GNUstep/System/Library/Libraries -lobjc -lgnustep-base -fconstant-string-class=NSConstantString -std=c99), I get this error:

undefined referenceto `__objc_class_name_NSApplication'
collect2: ld returned 1 exit status

I can #import fine, but when I try to call NSApplication I get this error. How can I fix this?

Originally posted 2013-11-09 20:51:01.