anchor.diff:        ln -s $lispdir $out/share/emacs/site-lisp
       '';
     })).override {
  -    haskell-src-exts = self.haskell-src-exts_1_19_0;
  +    haskell-src-exts = self.haskell-src-exts_1_19_1;
     };
   
     # # Make elisp files available at a location where people expect it.
  
positive.code:     '';
      doCheck = false; # https://github.com/chrisdone/hindent/issues/299
    })).override {
      haskell-src-exts = self.haskell-src-exts_1_19_0;
    };
  
    # https://github.com/yesodweb/Shelly.hs/issues/106
  
negative.code:   };
  
    # Needs new version.
    haskell-src-exts-simple = super.haskell-src-exts-simple.override { haskell-src-exts = self.haskell-src-exts_1_19_1; };
  
    # Test suite fails a QuickCheck property.
    optparse-applicative_0_13_0_0 = dontCheck super.optparse-applicative_0_13_0_0;
  