self: super: {
  myHaskellPackages = libProf: self: super:
    with super.haskell.lib; let pkg = self.callPackage; in rec {
    mkDerivation = pkg: super.mkDerivation (pkg // {
      enableLibraryProfiling = libProf;
      enableExecutableProfiling = false;
    });
  };
  haskell881Packages = with self; super.haskell.packages.ghc881.override {
    overrides = helf: huper: (myHaskellPackages false helf huper)
      // (with super.haskell.lib; {
          happy = dontCheck (doJailbreak
                    (huper.callHackage "happy" "1.19.10" {}));
         });
  };
}