Linker bug

gistfile1.txt

error MT2001: Could not link assemblies. Reason: Object reference not set to an instance of an object
--- inner exception
System.NullReferenceException: Object reference not set to an instance of an object
  at Mono.Cecil.Mixin.GetNestedType (Mono.Cecil.TypeDefinition self, System.String name) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.TypeParser.TryGetDefinition (Mono.Cecil.ModuleDefinition module, Mono.Cecil.Type type_info, Mono.Cecil.TypeReference& type) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.TypeParser.GetTypeReference (Mono.Cecil.ModuleDefinition module, Mono.Cecil.Type type_info) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.TypeParser.ParseType (Mono.Cecil.ModuleDefinition module, System.String fullname) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.SignatureReader.ReadTypeReference () [0x00000] in <filename unknown>:0 
  at Mono.Cecil.SignatureReader.ReadCustomAttributeElementValue (Mono.Cecil.TypeReference type) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.SignatureReader.ReadCustomAttributeElement (Mono.Cecil.TypeReference type) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.SignatureReader.ReadCustomAttributeFixedArgument (Mono.Cecil.TypeReference type) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.SignatureReader.ReadCustomAttributeConstructorArguments (Mono.Cecil.CustomAttribute attribute, Mono.Collections.Generic.Collection`1 parameters) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.MetadataReader.ReadCustomAttributeSignature (Mono.Cecil.CustomAttribute attribute) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.CustomAttribute.<Resolve>m__1 (Mono.Cecil.CustomAttribute attribute, Mono.Cecil.MetadataReader reader) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.ModuleDefinition.Read[CustomAttribute,CustomAttribute] (Mono.Cecil.CustomAttribute item, System.Func`3 read) [0x00000] in <filename unknown>:0 
  at Mono.Cecil.CustomAttribute.Resolve () [0x00000] in <filename unknown>:0 
  at Mono.Cecil.CustomAttribute.get_HasConstructorArguments () [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.MarkCustomAttributeArguments (Mono.Cecil.CustomAttribute ca) [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.MarkCustomAttribute (Mono.Cecil.CustomAttribute ca) [0x00000] in <filename unknown>:0 
  at Xamarin.Linker.Steps.MobileMarkStep.MarkCustomAttribute (Mono.Cecil.CustomAttribute ca) [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.MarkCustomAttributes (ICustomAttributeProvider provider) [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.ProcessMethod (Mono.Cecil.MethodDefinition method) [0x00000] in <filename unknown>:0 
  at Xamarin.Linker.Steps.CoreMarkStep.ProcessMethod (Mono.Cecil.MethodDefinition method) [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.ProcessQueue () [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.Process () [0x00000] in <filename unknown>:0 
  at Mono.Linker.Steps.MarkStep.Process (Mono.Linker.LinkContext context) [0x00000] in <filename unknown>:0 
  at Xamarin.Linker.Steps.MobileMarkStep.Process (Mono.Linker.LinkContext context) [0x00000] in <filename unknown>:0 
  at Xamarin.Linker.Steps.CoreMarkStep.Process (Mono.Linker.LinkContext context) [0x00000] in <filename unknown>:0 
  at MonoTouch.Tuner.MonoTouchMarkStep.Process (Mono.Linker.LinkContext context) [0x00000] in <filename unknown>:0 
  at Mono.Linker.Pipeline.Process (Mono.Linker.LinkContext context) [0x00000] in <filename unknown>:0 
  at MonoTouch.Tuner.Linker.Process (MonoTouch.Tuner.LinkerOptions options, MonoTouch.Tuner.MonoTouchLinkContext& context, System.Collections.Generic.List`1& assemblies) [0x00000] in <filename unknown>:0 
---
  at MonoTouch.Tuner.Linker.Process (MonoTouch.Tuner.LinkerOptions options, MonoTouch.Tuner.MonoTouchLinkContext& context, System.Collections.Generic.List`1& assemblies) [0x00000] in <filename unknown>:0 
  at MonoTouch.Target.LinkAssemblies (System.String main, System.Collections.Generic.List`1& assemblies, System.String output_dir, MonoTouch.Tuner.MonoTouchLinkContext& link_context) [0x00000] in <filename unknown>:0 
  at MonoTouch.Target.ManagedLink () [0x00000] in <filename unknown>:0 
  at MonoTouch.Target.ProcessAssemblies () [0x00000] in <filename unknown>:0 
  at MonoTouch.Target.BuildApp () [0x00000] in <filename unknown>:0 
  at MonoTouch.Application.BuildApp () [0x00000] in <filename unknown>:0 
  at MonoTouch.Application.Build () [0x00000] in <filename unknown>:0 
  at MTouch.Main2 (System.String[] args) [0x00000] in <filename unknown>:0 
  at MTouch.Main (System.String[] args) [0x00000] in <filename unknown>:0