anchor.diff:      "--with-daemon_groupname=atd"
     ];
   
  -  doCheck = false; # need "prove" tool
  +  doCheck = true;
   
     # Ensure that "batch" can invoke the setuid "at" wrapper, if it exists, or
     # else we get permission errors (on NixOS). "batch" is a shell script, so
  
positive.code: { stdenv, fetchurl, fetchpatch, bison, flex, pam
  , sendmailPath ? "/run/wrappers/bin/sendmail"
  , atWrapperPath ? "/run/wrappers/bin/at"
  }:
  
negative.code:     })
    ];
  
    nativeBuildInputs = [ bison flex perl /* for `prove` (tests) */ ];
  
    buildInputs = [ pam ];
  
  