Basically, I followed the instructions here: http://wiki.gnustep.org/index.php/GNUstep_under_Ubuntu_Linux
With the extra step of building the gui and back.
If I build and run a non-gui program, all works well. Only when I add something that uses the gui, like the following:
// Created by Tobias Lensing on 2/22/13.
#import <Foundation/Foundation.h>
#import <AppKit/AppKit.h>
#import <dispatch/dispatch.h>
int main(int argc, const char * argv[])
{
@autoreleasepool {
int multiplier = 7;
int (^myBlock)(int) = ^(int num) {
return num * multiplier;
};
NSLog(@"%d", myBlock(3));
dispatch_queue_t queue = dispatch_queue_create(NULL, NULL);
dispatch_sync(queue, ^{
printf("Hello, world from a dispatch queue!\n");
});
// dispatch_release(queue); // ARC takes care of this
}
@autoreleasepool {
[NSApplication sharedApplication];
NSRunAlertPanel(@"Test", @"Wow it works!", @"OK", nil, nil);
}
return 0;
}
I compile this with the following:
clang `gnustep-config --objc-flags` `gnustep-config --objc-libs` -fobjc-arc -fobjc-runtime=gnustep -fblocks -lobjc -ldispatch -lgnustep-gui test.m
It compiles and links with no errors.
When I run it, however, it spits out the following ugly-gram:
Hello, world from a dispatch queue!
Objective-C ABI Error: Loading modules from incompatible ABI's while loading .GSBackend.m
a.out: /home/lloyd/projects/ThirdParty/BuildGnuStep/libobjc2/loader.c:53: void __objc_exec_class(struct objc_module_abi_8 *): Assertion `objc_check_abi_verion(module)' failed.
Aborted (core dumped)
I have assured myself that there is no other version of libobjc (this is on a virtual machine so I can go back redo my steps).
Commenting out the following:
// [NSApplication sharedApplication];
// NSRunAlertPanel(@"Test", @"Wow it works!", @"OK", nil, nil);
and everything compiles and runs, aside from the GUI obviously.
How can I have two ABI's when I build everything from scratch? Do I need to configure the GUI differently? I've been puzzling over this for a couple of weeks.