anchor.diff:                               (builtins.stringLength path)
                                path;
         in
  -        builtins.filterSource (path: type: 
  +        builtins.filterSource (path: type:
             if builtins.any (x: x) (builtins.map (startsWith (relativePath path)) _exclude) then false
             else if builtins.any (x: x) (builtins.map (startsWith (relativePath path)) _include) then true
             else false
  
positive.code:     '' + lib.concatStrings cmds + ''
        HOME=$home_old
      '';
         
    startsWith = s: x:
      builtins.substring 0 (builtins.stringLength x) s == x;
  
  
negative.code: 
          inherit doCheck;
  
          checkPhase =
            if checkPhase != null
              then checkPhase
              else ''
                export LANG=en_US.UTF-8
                export LOCALE_ARCHIVE=${glibcLocales}/lib/locale/locale-archive
  
                flake8 --exclude=nix_run_setup.py,migrations/,build/
                pytest tests/
              '';
  
          postInstall = ''
            mkdir -p $out/bin
  