diff --git a/swh/lister/cran/lister.py b/swh/lister/cran/lister.py
--- a/swh/lister/cran/lister.py
+++ b/swh/lister/cran/lister.py
@@ -1,17 +1,22 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
-import subprocess
+
 import json
 import logging
 import pkg_resources
+import subprocess
+
 from collections import defaultdict
+from typing import List, Dict
 
 from swh.lister.cran.models import CRANModel
 
-from swh.scheduler.utils import create_task_dict
-from swh.core import utils
 from swh.lister.core.simple_lister import SimpleLister
+from swh.scheduler.utils import create_task_dict
+
+
+logger = logging.getLogger(__name__)
 
 
 class CRANLister(SimpleLister):
@@ -32,15 +37,17 @@
             kwargs.get('name'), origin_url, kwargs.get('version'),
             project_metadata=self.descriptions[kwargs.get('name')])
 
-    def r_script_request(self):
-        """Runs R script which uses inbuilt API to return a json
-            response containing data about all the R packages
+    def safely_issue_request(self, identifier: str) -> List[Dict]:
+        """Runs R script which uses inbuilt API to return a json response
+           containing data about all the R packages.
 
         Returns:
-            List of dictionaries
-            example
+            List of Dict about r packages.
+
+        Sample:
             [
-                {'Package': 'A3',
+              {
+                'Package': 'A3',
                 'Version': '1.0.0',
                 'Title':
                     'Accurate, Adaptable, and Accessible Error Metrics for
@@ -48,22 +55,27 @@
                 'Description':
                     'Supplies tools for tabulating and analyzing the results
                      of predictive models. The methods employed are ... '
-                }
-                {'Package': 'abbyyR',
+              },
+              {
+                'Package': 'abbyyR',
                 'Version': '0.5.4',
                 'Title':
                     'Access to Abbyy Optical Character Recognition (OCR) API',
                 'Description': 'Get text from images of text using Abbyy
-                                 Cloud Optical Character\n ...'
-                }
+                                Cloud Optical Character\n ...'
+               },
                 ...
             ]
+
         """
-        file_path = pkg_resources.resource_filename('swh.lister.cran',
-                                                    'list_all_packages.R')
-        response = subprocess.run(file_path, stdout=subprocess.PIPE,
-                                  shell=False)
-        return json.loads(response.stdout)
+        filepath = pkg_resources.resource_filename('swh.lister.cran',
+                                                   'list_all_packages.R')
+        logger.debug('script list-all-packages.R path: %s', filepath)
+        response = subprocess.run(
+            filepath, stdout=subprocess.PIPE, shell=False)
+        data = json.loads(response.stdout)
+        logger.debug('r-script-request: %s', data)
+        return data
 
     def get_model_from_repo(self, repo):
         """Transform from repository representation to model
@@ -87,36 +99,3 @@
 
         """
         return [self.get_model_from_repo(repo) for repo in response]
-
-    def ingest_data(self, identifier, checks=False):
-        """Rework the base ingest_data.
-           Request server endpoint which gives all in one go.
-
-           Simplify and filter response list of repositories.  Inject
-           repo information into local db. Queue loader tasks for
-           linked repositories.
-
-        Args:
-            identifier: Resource identifier (unused)
-            checks (bool): Additional checks required (unused)
-
-        """
-        response = self.r_script_request()
-        if not response:
-            return response, []
-        models_list = self.transport_response_simplified(response)
-        models_list = self.filter_before_inject(models_list)
-        all_injected = []
-        for models in utils.grouper(models_list, n=10000):
-            models = list(models)
-            logging.debug('models: %s' % len(models))
-            # inject into local db
-            injected = self.inject_repo_data_into_db(models)
-            # queue workers
-            self.create_missing_origins_and_tasks(models, injected)
-            all_injected.append(injected)
-            # flush
-            self.db_session.commit()
-            self.db_session = self.mk_session()
-
-        return response, all_injected