slurm extra lines does not work as expected: see change below

        lines.append("#SBATCH --output={}/{}.log".format(self.logs, self.job_name))
         if self.args.slurm_extra_lines is not None:
             slurm_extra_lines = " ".join(
-                ["--{}".format(lin) for lin in self.args.extra_lines.split()]
+                ["--{}".format(lin) for lin in self.args.slurm_extra_lines.split()]
             )
             for line in slurm_extra_lines.split():
                 lines.append("#SBATCH {}".format(line))