Unity script won't update after first successful weaving with Mono.Cecil

Question

I'm using Mono.Cecil to modify assemblies post compilation within Unity (I'm using this implementation of Mono.Cecil). For some reason, if I add a field to a type in an assembly, and the type of the field is a delegate type that I've defined, scripts in the assembly don't appear to update after the first successful modification/weaving.

The following code runs correctly every time I recompile, but if I attempt to replace PropertyChangedEventHandler with a custom delegate type, the assembly compiles and weaves correctly only once, then refuses to compile/update with newer script changes. It only works again if I restart Unity. I'm not receiving any error messages:

var handlerReference = typeDefinition.Module.ImportReference(typeof(System.ComponentModel.PropertyChangedEventHandler));
 
var fieldDef = new FieldDefinition(nameof(INotifyMethodCalled.MethodCalled), FieldAttributes.Private | FieldAttributes.NotSerialized, handlerReference);

typeDefinition.Fields.Add(fieldDef);

Any help would be greatly appreciated.

Answer 1

I just resolved my issue--the script doing the weaving was referencing the assembly it was weaving. This was the programmatic equivalent of a snake eating its tail and choking on it. The script using Mono.Cecil no longer references its target assembly.