anchor.diff:  
   ${opts.extra}
                 '';
  -            ctl = pkgs.writeScript "zope2-${name}-ctl"
  +            ctlScript = pkgs.writeScript "zope2-${name}-ctl-script"
                 ''#!${env}/bin/python
   
   import sys
  
positive.code: if __name__ == '__main__':
      sys.exit(plone.recipe.zope2instance.ctl.main(
          ["-C", "${conf}"]
          + sys.argv[1:]))'';
            in {
              description = "zope2 ${name} instance";
              after = [ "network.target" ];  # with RelStorage also add "postgresql.service"
  
negative.code:               '';
              env = pkgs.buildEnv {
                name = "zope2-${name}-env";
                paths = [
                  pkgs.python27
                  pkgs.python27Packages.recursivePthLoader
                  pkgs.python27Packages."plone.recipe.zope2instance"
                ] ++ attrValues pkgs.python27.modules
                  ++ opts.packages;
                postBuild =
                  ''
                  echo "#!$out/bin/python" > $out/bin/interpreter
                  cat ${interpreter} >> $out/bin/interpreter
                  '';
              };
              conf = pkgs.writeText "zope2-${name}-conf"
                ''%define INSTANCEHOME ${env}
  