error:
       … while evaluating a path segment
         at /pwd/lang/eval-fail-nested-list-items.nix:11:6:
           10|
           11| "" + (let v = [ [ 1 2 3 4 5 6 7 8 ] [1 2 3 4]]; in builtins.deepSeq v v)
             |      ^
           12|

       error: cannot coerce a list to a string: [ [ 1 2 3 4 5 6 7 8 ] [ 1 «3 items elided» ] ]
