Internal Compiler Error #3 (ILGenerator Emit Issue)

Questions & Answers
1

I am getting an Internal Compiler Error. The research I have done so far on this one points to the only solution being to upgrade the Mono system to a newer version. Since this is Unity 4.0 I don’t know how I can possibly do that and even if Unity will upgrade any time soon. What do I do about that?

Here is the error:

Internal compiler error. See the console log for more information. output was:
Unhandled Exception: System.ArgumentException: Trying to emit a local from a different ILGenerator.
  at System.Reflection.Emit.ILGenerator.Emit (OpCode opcode, System.Reflection.Emit.LocalBuilder local) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.LocalTemporary.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.MemberExpr.EmitInstance (Mono.CSharp.EmitContext ec, Boolean prepare_for_load) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.FieldExpr.Emit (Mono.CSharp.EmitContext ec, Boolean leave_copy) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.HoistedVariable.Emit (Mono.CSharp.EmitContext ec, Boolean leave_copy) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.VariableReference.Emit (Mono.CSharp.EmitContext ec, Boolean leave_copy) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.VariableReference.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Argument.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Arguments.Emit (Mono.CSharp.EmitContext ec, Boolean dup_args, Mono.CSharp.LocalTemporary this_arg) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Invocation.EmitCall (Mono.CSharp.EmitContext ec, Boolean is_base, Mono.CSharp.Expression instance_expr, System.Reflection.MethodBase method, Mono.CSharp.Arguments Arguments, Location loc, Boolean dup_args, Boolean omit_args) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Invocation.EmitCall (Mono.CSharp.EmitContext ec, Boolean is_base, Mono.CSharp.Expression instance_expr, System.Reflection.MethodBase method, Mono.CSharp.Arguments Arguments, Location loc) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.MethodGroupExpr.EmitCall (Mono.CSharp.EmitContext ec, Mono.CSharp.Arguments arguments) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Invocation.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Invocation.EmitStatement (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.StatementExpression.DoEmit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Statement.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Block.DoEmit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Block.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.ExplicitBlock.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.ToplevelBlock.Emit (Mono.CSharp.EmitContext ec) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.MethodData.Emit (Mono.CSharp.DeclSpace parent) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.AbstractPropertyEventMethod.Emit (Mono.CSharp.DeclSpace parent) [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Event.Emit () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.TypeContainer.EmitType () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.RootContext.EmitCode () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Driver.Compile () [0x00000] in <filename unknown>:0 
  at Mono.CSharp.Driver.Main (System.String[] args) [0x00000] in <filename unknown>:0
2

From everything I can tell these Internal Compiler errors happen when I try to include a .dll file that requires .NET functionality that is higher than 2.0 and part of the bleeding edge stuff included in Unity’s mono. That is probably why it is called bleeding edge, eh?

Anyway, the answer is just trial and error. Some newer .NET stuff works and some just doesn’t even though it is included and supposedly “in there”.

3

//this.channels.ForEach (chn => chn.nodes.ForEach (nd => nd.onStart.AddListener(value)));<-- this cause same error.

//solution

  foreach(SequenceChannel channel in this.channels)
					         foreach(SequenceNode node in channel.nodes)
									node.onStart.AddListener(value);
						}

It is obvious that many stuff in Mono towards .NET are underdeveloped.

4

I had what seemed to be several warnings appearing as errors!
When I scrolled down through the warnings, I noticed there truly was an error listed at the very end.

ERROR…
“Unhandled Exception: System.ArgumentException: Trying to emit a local from a different ILGenerator”

CAUSE…
The error occurred because I had just put a TRY CATCH statement inside a COROUTINE. Unity doesn’t like that!

SOLUTION…
I resolved the error be removing all Try Catch statements from all Coroutines.