ilrepack does not indicate anywhere that line numbering depends on resolving IKVM.Runtime. It's not a dependency of ilrepack, so unless it just happens to be available to be resolved, you will get an error complaining it cannot be resolved. Tracking down why that's even a problem could be rather confusing, since it may not be a transitive dependency of your project. At least mentioning that line numbering relies on this being available would be nice. I only figured out what was going on when I started looking at the source and saw IKVMLineIndexer.cs was injecting references to it.