error:
       … in the argument of the not operator
         at /pwd/lang/eval-fail-not-throws.nix:1:4:
            1| ! (throw "uh oh!")
             |    ^
            2|

       … while calling the 'throw' builtin
         at /pwd/lang/eval-fail-not-throws.nix:1:4:
            1| ! (throw "uh oh!")
             |    ^
            2|

       error: uh oh!