anchor.diff:  let installSanePath = path: ''
         if [ -e "${path}/lib/sane" ]; then
           find "${path}/lib/sane" -maxdepth 1 -not -type d | while read backend; do
  -          ln -s "$backend" "$out/lib/sane/$(basename "$backend")"
  +          symlink "$backend" "$out/lib/sane/$(basename "$backend")"
           done
         fi
   
  
positive.code:   phases = "installPhase";
  
    installPhase = ''
      mkdir -p $out/etc/sane.d $out/etc/sane.d/dll.d $out/lib/sane
    '' + concatMapStrings installSanePath paths;
  }
  
negative.code:           if [ "$name" = "dll.conf" ] || [ "$name" = "saned.conf" ] || [ "$name" = "net.conf" ]; then
              cat "$conf" >> "$out/etc/sane.d/$name"
            else
              symlink "$conf" "$out/etc/sane.d/$name"
            fi
          done
        fi
  
        if [ -e "${path}/etc/sane.d/dll.d" ]; then
          find "${path}/etc/sane.d/dll.d" -maxdepth 1 -not -type d | while read conf; do
            symlink "$conf" "$out/etc/sane.d/dll.d/$(basename $conf)"
          done
        fi
      '';
  