{ mkDerivation, base, deepseq, fetchurl }:
mkDerivation {
  pname = "Only";
  version = "0.1";
  src = fetchurl {
    url = "http://example.org/";
    sha256 = "abc";
  };
  libraryHaskellDepends = [ base deepseq ];
  description = "The 1-tuple type or single-value \"collection\"";
  license = stdenv.lib.licenses.bsd3;
}