tests.fetchtorrent: avoid builtins.convertHash

  # Fixed output derivation hash is identical for all derivations: the empty

  # directory.

  fetchtorrentWithHash =

    args:

    fetchtorrent (

      {

        hash = builtins.convertHash {

          hash = emptyDirectory.outputHash;

          toHashFormat = "sri";

          hashAlgo = emptyDirectory.outputHashAlgo;

        };

      }

      // args

    );

    args: fetchtorrent ({ hash = "sha256-pQpattmS9VmO3ZIQUFn66az8GSmB4IvYhTTCFn6SUmo="; } // args);

in

# Seems almost but not quite worth using lib.mapCartesianProduct...

builtins.mapAttrs (n: v: testers.invalidateFetcherByDrvHash fetchtorrentWithHash v) {