Re: "shadow"...Eh, there are a few very specific usages of it like a local shadowing a parameter or nested scope shadowing outer scope and so on, but the word/idea generally captures the ' must both be "x" ' idea fundamental to this bug, at least to my ears/eyeballs.
Anyway your reproductions are very small/self-contained. I expect Nim core can fix it or at least produce a better error message or at the very least document the limitation (unless it already is documented).
