diff --git a/swh/lister/bitbucket/tasks.py b/swh/lister/bitbucket/tasks.py
index 972ff13..5299de1 100644
--- a/swh/lister/bitbucket/tasks.py
+++ b/swh/lister/bitbucket/tasks.py
@@ -1,58 +1,61 @@
 # Copyright (C) 2017-2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 from celery import group
 
 from swh.scheduler.celery_backend.config import app
 
 from .lister import BitBucketLister
 
 GROUP_SPLIT = 10000
 
 
 def new_lister(api_baseurl='https://api.bitbucket.org/2.0'):
     return BitBucketLister(api_baseurl=api_baseurl)
 
 
 @app.task(name='swh.lister.bitbucket.tasks.IncrementalBitBucketLister',
           bind=True)
 def incremental_bitbucket_lister(self, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister = new_lister(**lister_args)
     lister.run(min_bound=lister.db_last_index(), max_bound=None)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.bitbucket.tasks.RangeBitBucketLister',
           bind=True)
 def range_bitbucket_lister(self, start, end, **lister_args):
-    self.log.debug('%s(start=%s, end=%d), lister_args=%s' % (
+    self.log.debug('%s(start=%s, end=%s), lister_args=%s' % (
         self.name, start, end, lister_args))
     lister = new_lister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.bitbucket.tasks.FullBitBucketRelister',
           bind=True)
 def full_bitbucket_relister(self, split=None, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister = new_lister(**lister_args)
     ranges = lister.db_partition_indices(split or GROUP_SPLIT)
     random.shuffle(ranges)
     promise = group(range_bitbucket_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
-    promise.save()  # so that we can restore the GroupResult in tests
+    try:
+        promise.save()  # so that we can restore the GroupResult in tests
+    except NotImplementedError:
+        self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
 @app.task(name='swh.lister.bitbucket.tasks.ping',
           bind=True)
 def ping(self):
     self.log.debug(self.name)
     return 'OK'
diff --git a/swh/lister/github/tasks.py b/swh/lister/github/tasks.py
index 372299f..625f5f5 100644
--- a/swh/lister/github/tasks.py
+++ b/swh/lister/github/tasks.py
@@ -1,59 +1,62 @@
 # Copyright (C) 2017-2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 
 from celery import group
 
 from swh.scheduler.celery_backend.config import app
 
 from swh.lister.github.lister import GitHubLister
 
 GROUP_SPLIT = 10000
 
 
 def new_lister(api_baseurl='https://api.github.com', **kw):
     return GitHubLister(api_baseurl=api_baseurl, **kw)
 
 
 @app.task(name='swh.lister.github.tasks.IncrementalGitHubLister',
           bind=True)
 def incremental_github_lister(self, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister = new_lister(**lister_args)
     lister.run(min_bound=lister.db_last_index(), max_bound=None)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.github.tasks.RangeGitHubLister',
           bind=True)
 def range_github_lister(self, start, end, **lister_args):
     self.log.debug('%s(start=%s, end=%d), lister_args=%s' % (
         self.name, start, end, lister_args))
     lister = new_lister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.github.tasks.FullGitHubRelister',
           bind=True)
 def full_github_relister(self, split=None, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister = new_lister(**lister_args)
     ranges = lister.db_partition_indices(split or GROUP_SPLIT)
     random.shuffle(ranges)
     promise = group(range_github_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
-    promise.save()  # so that we can restore the GroupResult in tests
+    try:
+        promise.save()  # so that we can restore the GroupResult in tests
+    except NotImplementedError:
+        self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
 @app.task(name='swh.lister.github.tasks.ping',
           bind=True)
 def ping(self):
     self.log.debug(self.name)
     return 'OK'
diff --git a/swh/lister/gitlab/tasks.py b/swh/lister/gitlab/tasks.py
index 65b8b4a..739d95a 100644
--- a/swh/lister/gitlab/tasks.py
+++ b/swh/lister/gitlab/tasks.py
@@ -1,68 +1,71 @@
 # Copyright (C) 2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 
 from celery import group
 
 from swh.scheduler.celery_backend.config import app
 
 from .. import utils
 from .lister import GitLabLister
 
 
 NBPAGES = 10
 
 
 def new_lister(api_baseurl='https://gitlab.com/api/v4',
                instance=None, sort='asc', per_page=20):
     return GitLabLister(
         api_baseurl=api_baseurl, instance=instance, sort=sort,
         per_page=per_page)
 
 
 @app.task(name='swh.lister.gitlab.tasks.IncrementalGitLabLister',
           bind=True)
 def incremental_gitlab_lister(self, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister_args['sort'] = 'desc'
     lister = new_lister(**lister_args)
     total_pages = lister.get_pages_information()[1]
     # stopping as soon as existing origins for that instance are detected
     lister.run(min_bound=1, max_bound=total_pages, check_existence=True)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.gitlab.tasks.RangeGitLabLister',
           bind=True)
 def range_gitlab_lister(self, start, end, **lister_args):
     self.log.debug('%s(start=%s, end=%d), lister_args=%s' % (
         self.name, start, end, lister_args))
     lister = new_lister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
     self.log.debug('%s OK' % (self.name))
 
 
 @app.task(name='swh.lister.gitlab.tasks.FullGitLabRelister',
           bind=True)
 def full_gitlab_relister(self, **lister_args):
     self.log.debug('%s, lister_args=%s' % (
         self.name, lister_args))
     lister = new_lister(**lister_args)
     _, total_pages, _ = lister.get_pages_information()
     ranges = list(utils.split_range(total_pages, NBPAGES))
     random.shuffle(ranges)
     promise = group(range_gitlab_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
-    promise.save()
+    try:
+        promise.save()
+    except NotImplementedError:
+        self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
 @app.task(name='swh.lister.gitlab.tasks.ping',
           bind=True)
 def ping(self):
     self.log.debug(self.name)
     return 'OK'