> Tricky to fix, too, since its a read-only binding plus you can't
> simply reference Fred anymore at all.  I had to:
>
>    [ (Smalltalk association at: #Fred) value: (Smalltalk
> allClassesAndTraits detect: [ : e | e name = #Fred) ]
>       on: AttemptToWriteReadOnlyGlobal
>       do: [ : noti | noti resume: true ]

Should have pasted it:

 [ (Smalltalk associationOrUndeclaredAt: #Fred) value: (Smalltalk
allClassesAndTraits detect: [ : e | e name = #Fred ]) ]
      on: AttemptToWriteReadOnlyGlobal
      do: [ : noti | noti resume: true ]

So, the problem develops in the Environment's 'references' Dictionary...