error:
       … while evaluating fallback for missing attribute 'toebeans'
         at /pwd/in.nix:6:23:
            5|
            6| in catSet.toebeans or thisThrows
             |                       ^
            7|

       … while evaluating thisThrows
         at /pwd/in.nix:6:23:
            5|
            6| in catSet.toebeans or thisThrows
             |                       ^
            7|

       … caused by explicit throw
         at /pwd/in.nix:2:16:
            1| let
            2|   thisThrows = throw "meow";
             |                ^
            3|

       error: meow