"attributes elided" placeholder's count can underflow

[roberth]

Steps To Reproduce

$ nix run nix/2.23.1 -- eval --expr '"" + (let v = { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; b = 1; c = 1; }; }; in builtins.dee>
error:
       … while evaluating a path segment
         at «string»:1:6:
            1| "" + (let v = { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; b = 1; c = 1; }; }; in builtins.deepSeq v v)
             |      ^

       error: cannot coerce a set to a string: { a = { a = 1; b = 2; c = 1; d = 1; e = 1; f = 1; g = 1; h = 1; }; b = { a = 1; «4294967289 attributes elided» }; }

Expected behavior

Show the correct number.

nix-env --version output

Additional context

Priorities

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