{ fetchurl }:

fetchurl {
  url = "https://github.com/commercialhaskell/all-cabal-hashes/archive/56955295749aea09bd42591cd506c2616d48ebfd.tar.gz";
  sha256 = "17c8a1wj1jxr14sxvwq0i9kidwycz2hkl1ls51yfz14anylxr84l";
}