```
at: (16:30) in file: /nix/store/ad2z4crkvdsppp2rlws1h6x48xacrr33-source/flake.nix

    15|                 name = "erlang-representer";
    16|                 version = "${self.rev}-${self.lastModifiedDate}";
      |                              ^
    17| 

attribute 'rev' missing
(use '--show-trace' to show detailed location information)

```