anchor.diff:    buildInputs = [ makeWrapper ];
   
     installPhase = ''
  -      mkdir -p $out
  -      rm bin/*.bat
  -      mv * $out
  -      # put docs in correct subdirectory
  -      mkdir -p $out/share/doc
  -      mv $out/doc $out/share/doc/${name}
  -      mv $out/man $out/share/man
  +    runHook preInstall
  +    mkdir -p $out
  +    rm bin/*.bat
  +    mv * $out
  +    # put docs in correct subdirectory
  +    mkdir -p $out/share/doc
  +    mv $out/doc $out/share/doc/${name}
  +    mv $out/man $out/share/man
       for p in $(ls $out/bin/) ; do
           wrapProgram $out/bin/$p \
             --prefix PATH ":" ${coreutils}/bin \
             --prefix PATH ":" ${gnugrep}/bin \
             --prefix PATH ":" ${jre}/bin \
             --set JAVA_HOME ${jre}
  -      done
  +    done
  +    runHook postInstall
     '';
   
     doInstallCheck = true;
  
positive.code:     };
  
      "2.13" = {
        version = "2.13.4";
        sha256 = "1alcnzmxga00nsvgy8yky91zw5b4q0xg2697vrrdgjlglpxiqwdw";
        pname = "scala_2_13";
      };
    };
  
negative.code: { stdenv, lib, fetchurl, makeWrapper, jre, gnugrep, coreutils
  , writeScript, common-updater-scripts, git, gnused, nix, nixfmt, majorVersion }:
  
  with lib;
  