rustPlatform.fetchCargoTarball: default outputHashAlgo to sha256

} @ args:

let hash_ =

  if args ? hash then { outputHashAlgo = null; outputHash = args.hash; }

  if args ? hash then

    {

      outputHashAlgo = if args.hash == "" then "sha256" else null;

      outputHash = args.hash;

    }

  else if args ? sha256 then { outputHashAlgo = "sha256"; outputHash = args.sha256; }

  else throw "fetchCargoTarball requires a hash for ${name}";

in stdenv.mkDerivation ({