A dirty solution from upstream to make GModel loading work again.  The
clean fix is going to be ABI-incompatible.
http://thread.gmane.org/gmane.comp.lib.gnustep.devel/9347


2010-08-29  Fred Kiefer  <FredKiefer@gmx.de>

	* Source/GSGModelLoader.m (-dataForFile:)
	(-loadModelData:externalNameTable:withZone:): New methods.

--- gnustep-gui-0.18.0.orig/Source/GSGModelLoader.m
+++ gnustep-gui-0.18.0/Source/GSGModelLoader.m
@@ -109,4 +109,20 @@
 
   return NO;
 }
+
+- (NSData *) dataForFile: (NSString *)fileName
+{
+  // Horrible hack
+  return (NSData *)fileName;
+}
+
+- (BOOL) loadModelData: (NSData *)data
+     externalNameTable: (NSDictionary *)context
+              withZone: (NSZone *)zone
+{
+  // Horrible hack
+  return [self loadModelFile: (NSString *)data
+           externalNameTable: context
+                    withZone: zone];
+}
 @end