Incorrect implicit ambiguity resolution

[Keno]

Here is another MWE for (#57328 (comment)) here for https://s3.amazonaws.com/julialang-reports/nanosoldier/pkgeval/by_hash/7825364_vs_d63aded/BrillouinZoneMeshes.primary.log:

module M
    module A
        export S
    end
    using .A
    module B
        abstract type S end
        export S
    end
    using .B
    S
end

During package precompilation you don't really get a good error message but pasting into the REPL you see

ERROR: UndefVarError: `S` not defined in `Main.M`
Hint: It looks like two or more modules export different bindings with this name, resulting in ambiguity. Try explicitly importing it from a particular module, or qualifying the name with the module it should come from.

(And no, I don't know why people write their code like this...)

Originally posted by @KristofferC in #57328