Never mind. I “up’ed” my packages; quit Julia; restarted Julia in the same terminal session. I’d been in the same terminal session for about a week. That’s just asking for trouble. Memory corruption or Revise got confused. Quit terminal. Open new terminal. Problem gone.
Don’t worry about this. Long sessions are always risky. Pays to purge every day. And it’s good practice to make things clean and repeatable.
You probably tried to redefine the struct Variable with a different definition. This is not possible in Julia and indeed the only solution is to restart the whole Julia process if you wish to redefine it with the same name.
I can do a text search across all files in the project. No such thing.
What I pasted is the error message. It refers to something that isn’t present. I suspect it was in a package that was subsequently upgraded, which is why it disappeared when I restarted terminal and Julia—with no change to my code.
Let’s let it go. It’s one those mysteries. If it had persisted, then there’d be something to figure out.