anchor.diff:  		"$out/libexec/git-core/$prog"
          done
        '' else ''
  -      # Don't wrap Tcl/Tk, replace them by notification scripts
  -       for prog in bin/gitk libexec/git-core/git-gui
  -       do
  +       # Don't wrap Tcl/Tk, replace them by notification scripts
  +       for prog in bin/gitk libexec/git-core/git-gui; do
            notSupported "$out/$prog" \
                         "reinstall with config git = { guiSupport = true; } set"
          done
  
positive.code:    # multiple times into $out so replace duplicates by symlinks because I
     # haven't tested whether the nix distribution system can handle hardlinks.
     # This reduces the size of $out from 115MB down to 13MB on x86_64-linux!
     + ''#
        declare -A seen
        shopt -s globstar
        for f in "$out/"**; do
  
negative.code:           rm "$f"; ln -v -s "''\${seen["$sum"]}" "$f"
          fi
        done
       '';
  
    enableParallelBuilding = true;
  