diff --git a/addons/mass_mailing_sms/controllers/main.py b/addons/mass_mailing_sms/controllers/main.py
index 35aee22dbd1..000b26f62d7 100644
--- a/addons/mass_mailing_sms/controllers/main.py
+++ b/addons/mass_mailing_sms/controllers/main.py
@@ -89,10 +89,10 @@ class MailingSMSController(http.Controller):
             'unsubscribe_error': unsubscribe_error,
         })
 
-    @http.route('/r/<string:code>/s/<int:sms_sms_id>', type='http', auth="public")
-    def sms_short_link_redirect(self, code, sms_sms_id, **post):
-        if sms_sms_id:
-            trace_id = request.env['mailing.trace'].sudo().search([('sms_sms_id_int', '=', int(sms_sms_id))]).id
+    @http.route('/r/<string:code>/s/<int:sms_id_int>', type='http', auth="public")
+    def sms_short_link_redirect(self, code, sms_id_int, **post):
+        if sms_id_int:
+            trace_id = request.env['mailing.trace'].sudo().search([('sms_id_int', '=', int(sms_id_int))]).id
         else:
             trace_id = False
 
diff --git a/addons/mass_mailing_sms/models/mailing_trace.py b/addons/mass_mailing_sms/models/mailing_trace.py
index b884c71b402..f485c9b29ee 100644
--- a/addons/mass_mailing_sms/models/mailing_trace.py
+++ b/addons/mass_mailing_sms/models/mailing_trace.py
@@ -16,9 +16,9 @@ class MailingTrace(models.Model):
     trace_type = fields.Selection(selection_add=[
         ('sms', 'SMS')
     ], ondelete={'sms': 'set default'})
-    sms_sms_id = fields.Many2one('sms.sms', string='SMS', index='btree_not_null', ondelete='set null')
-    sms_sms_id_int = fields.Integer(
-        string='SMS ID (tech)',
+    sms_id = fields.Many2one('sms.sms', string='SMS', store=False, compute='_compute_sms_id')
+    sms_id_int = fields.Integer(
+        string='SMS ID',
         index='btree_not_null'
         # Integer because the related sms.sms can be deleted separately from its statistics.
         # However, the ID is needed for several action and controllers.
@@ -46,11 +46,21 @@ class MailingTrace(models.Model):
         ('sms_rejected', 'Rejected'),
     ])
 
+    @api.depends('sms_id_int', 'trace_type')
+    def _compute_sms_id(self):
+        self.sms_id = False
+        sms_traces = self.filtered(lambda t: t.trace_type == 'sms' and bool(t.sms_id_int))
+        if not sms_traces:
+            return
+        existing_sms_ids = self.env['sms.sms'].sudo().search([
+            ('id', 'in', sms_traces.mapped('sms_id_int')), ('to_delete', '!=', True)
+        ]).ids
+        for sms_trace in sms_traces.filtered(lambda n: n.sms_id_int in set(existing_sms_ids)):
+            sms_trace.sms_id = sms_trace.sms_id_int
+
     @api.model_create_multi
     def create(self, values_list):
         for values in values_list:
-            if 'sms_sms_id' in values:
-                values['sms_sms_id_int'] = values['sms_sms_id']
             if values.get('trace_type') == 'sms' and not values.get('sms_code'):
                 values['sms_code'] = self._get_random_code()
         return super(MailingTrace, self).create(values_list)
diff --git a/addons/mass_mailing_sms/models/sms_sms.py b/addons/mass_mailing_sms/models/sms_sms.py
index 768554a3961..03ffe03d8d0 100644
--- a/addons/mass_mailing_sms/models/sms_sms.py
+++ b/addons/mass_mailing_sms/models/sms_sms.py
@@ -10,7 +10,10 @@ class SmsSms(models.Model):
     _inherit = ['sms.sms']
 
     mailing_id = fields.Many2one('mailing.mailing', string='Mass Mailing')
-    mailing_trace_ids = fields.One2many('mailing.trace', 'sms_sms_id', string='Statistics')
+    # Linking to another field than the comodel id allows to use the ORM to create
+    # "linked" records (see _prepare_sms_values) without adding a foreign key.
+    # See commit message for why this is useful.
+    mailing_trace_ids = fields.One2many('mailing.trace', 'sms_id_int', string='Statistics')
 
     def _update_body_short_links(self):
         """ Override to tweak shortened URLs by adding statistics ids, allowing to
diff --git a/addons/mass_mailing_sms/tests/common.py b/addons/mass_mailing_sms/tests/common.py
index 292d2b22295..36502491a68 100644
--- a/addons/mass_mailing_sms/tests/common.py
+++ b/addons/mass_mailing_sms/tests/common.py
@@ -90,7 +90,7 @@ class MassSMSCase(SMSCase, MockLinkTracker):
             )
             self.assertTrue(len(trace) == 1,
                             'SMS: found %s notification for number %s, (status: %s) (1 expected)' % (len(trace), number, status))
-            self.assertTrue(bool(trace.sms_sms_id_int))
+            self.assertTrue(bool(trace.sms_id_int))
 
             if check_sms:
                 if status in {'process', 'pending', 'sent'}:
@@ -156,8 +156,8 @@ class MassSMSCase(SMSCase, MockLinkTracker):
             if '/r/' in url:  # shortened link, like 'http://localhost:8069/r/LBG/s/53'
                 parsed_url = werkzeug.urls.url_parse(url)
                 path_items = parsed_url.path.split('/')
-                code, sms_sms_id = path_items[2], int(path_items[4])
-                trace_id = self.env['mailing.trace'].sudo().search([('sms_sms_id_int', '=', sms_sms_id)]).id
+                code, sms_id_int = path_items[2], int(path_items[4])
+                trace_id = self.env['mailing.trace'].sudo().search([('sms_id_int', '=', sms_id_int)]).id
 
                 self.env['link.tracker.click'].sudo().add_click(
                     code,
diff --git a/addons/mass_mailing_sms/views/mailing_trace_views.xml b/addons/mass_mailing_sms/views/mailing_trace_views.xml
index 44cdb1188e9..ca1dd9026c7 100644
--- a/addons/mass_mailing_sms/views/mailing_trace_views.xml
+++ b/addons/mass_mailing_sms/views/mailing_trace_views.xml
@@ -6,8 +6,8 @@
         <field name="inherit_id" ref="mass_mailing.mailing_trace_view_search"/>
         <field name="arch" type="xml">
            <xpath expr="//field[@name='email']" position="after">
-                <field name="sms_sms_id_int"/>
-                <field name="sms_sms_id"/>
+                <field name="sms_id_int"/>
+                <field name="sms_id"/>
                 <field name="sms_number"/>
            </xpath>
         </field>
@@ -68,7 +68,7 @@
                 <field name="sms_number" invisible="trace_type != 'sms'"/>
             </xpath>
             <xpath expr="//field[@name='message_id']" position="after">
-                <field name="sms_sms_id_int" string="SMS ID"
+                <field name="sms_id_int" string="SMS ID"
                     invisible="trace_type != 'sms'"
                     groups="base.group_no_one"/>
                 <field name="sms_code" invisible="trace_type != 'sms'"
@@ -118,14 +118,14 @@
                             <field name="trace_type" invisible="1"/>
                             <field name="sms_number"/>
                             <field name="mass_mailing_id"/>
-                            <field name="sms_sms_id_int" string="SMS ID" groups="base.group_no_one"/>
+                            <field name="sms_id_int" string="SMS ID" groups="base.group_no_one"/>
                             <field name="sms_code" groups="base.group_no_one"/>
                         </group>
                         <group string="Marketing">
                             <field name="campaign_id" groups="mass_mailing.group_mass_mailing_campaign"/>
                             <field name="medium_id"/>
                             <field name="source_id"/>
-                            <field name="sms_sms_id" groups="base.group_no_one"/>
+                            <field name="sms_id" groups="base.group_no_one" invisible="not sms_id"/>
                         </group>
                     </group>
                 </sheet>
diff --git a/addons/sms/controllers/main.py b/addons/sms/controllers/main.py
index dfa96bd4e24..b4931ddc4c4 100644
--- a/addons/sms/controllers/main.py
+++ b/addons/sms/controllers/main.py
@@ -36,7 +36,7 @@ class SmsController(Controller):
                 else:
                     sms_trackers_sudo._action_update_from_provider_error(iap_status)
             all_uuids += uuids
-        http.request.env['sms.sms'].sudo().search([('uuid', 'in', all_uuids)]).unlink()
+        request.env['sms.sms'].sudo().search([('uuid', 'in', all_uuids), ('to_delete', '=', False)]).to_delete = True
         return 'OK'
 
     @staticmethod
diff --git a/addons/sms/models/mail_notification.py b/addons/sms/models/mail_notification.py
index fe9d5567051..e8e1aea2fbf 100644
--- a/addons/sms/models/mail_notification.py
+++ b/addons/sms/models/mail_notification.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 
-from odoo import fields, models
+from odoo import api, fields, models
 
 
 class MailNotification(models.Model):
@@ -10,7 +10,9 @@ class MailNotification(models.Model):
     notification_type = fields.Selection(selection_add=[
         ('sms', 'SMS')
     ], ondelete={'sms': 'cascade'})
-    sms_id = fields.Many2one('sms.sms', string='SMS', index='btree_not_null', ondelete='set null')
+    sms_id_int = fields.Integer('SMS ID', index='btree_not_null')
+    # Used to give links on form view without foreign key. In most cases, you'd want to use sms_id_int or sms_tracker_ids.sms_uuid.
+    sms_id = fields.Many2one('sms.sms', string='SMS', store=False, compute='_compute_sms_id')
     sms_tracker_ids = fields.One2many('sms.tracker', 'mail_notification_id', string="SMS Trackers")
     sms_number = fields.Char('SMS Number')
     failure_type = fields.Selection(selection_add=[
@@ -28,3 +30,15 @@ class MailNotification(models.Model):
         ('sms_not_delivered', 'Not Delivered'),
         ('sms_rejected', 'Rejected'),
     ])
+
+    @api.depends('sms_id_int', 'notification_type')
+    def _compute_sms_id(self):
+        self.sms_id = False
+        sms_notifications = self.filtered(lambda n: n.notification_type == 'sms' and bool(n.sms_id_int))
+        if not sms_notifications:
+            return
+        existing_sms_ids = self.env['sms.sms'].sudo().search([
+            ('id', 'in', sms_notifications.mapped('sms_id_int')), ('to_delete', '!=', True)
+        ]).ids
+        for sms_notification in sms_notifications.filtered(lambda n: n.sms_id_int in set(existing_sms_ids)):
+            sms_notification.sms_id = sms_notification.sms_id_int
diff --git a/addons/sms/models/mail_thread.py b/addons/sms/models/mail_thread.py
index cd7a2c2f191..b1ab8a6916f 100644
--- a/addons/sms/models/mail_thread.py
+++ b/addons/sms/models/mail_thread.py
@@ -305,7 +305,7 @@ class MailThread(models.AbstractModel):
                 'res_partner_id': sms.partner_id.id,
                 'sms_number': sms.number,
                 'notification_type': 'sms',
-                'sms_id': sms.id,
+                'sms_id_int': sms.id,
                 'sms_tracker_ids': [Command.create({'sms_uuid': sms.uuid})] if sms.state == 'outgoing' else False,
                 'is_read': True,  # discard Inbox notification
                 'notification_status': 'ready' if sms.state == 'outgoing' else 'exception',
@@ -323,7 +323,7 @@ class MailThread(models.AbstractModel):
                         notif.write({
                             'notification_type': 'sms',
                             'notification_status': 'ready',
-                            'sms_id': sms.id,
+                            'sms_id_int': sms.id,
                             'sms_tracker_ids': [Command.create({'sms_uuid': sms.uuid})],
                             'sms_number': sms.number,
                         })
diff --git a/addons/sms/models/sms_sms.py b/addons/sms/models/sms_sms.py
index 7dbeb16da00..ca93fef8e43 100644
--- a/addons/sms/models/sms_sms.py
+++ b/addons/sms/models/sms_sms.py
@@ -63,6 +63,10 @@ class SmsSms(models.Model):
         ('sms_optout', 'Opted Out'),
     ], copy=False)
     sms_tracker_id = fields.Many2one('sms.tracker', string='SMS trackers', compute='_compute_sms_tracker_id')
+    to_delete = fields.Boolean(
+        'Marked for deletion', default=False,
+        help='Will automatically be deleted, while notifications will not be deleted in any case.'
+    )
 
     _sql_constraints = [
         ('uuid_unique', 'unique(uuid)', 'UUID must be unique'),
@@ -93,7 +97,7 @@ class SmsSms(models.Model):
           :param auto_commit: commit after each batch of SMS;
           :param raise_exception: raise if there is an issue contacting IAP;
         """
-        self = self.filtered(lambda sms: sms.state == 'outgoing')
+        self = self.filtered(lambda sms: sms.state == 'outgoing' and not sms.to_delete)
         for batch_ids in self._split_batch():
             self.browse(batch_ids)._send(unlink_failed=unlink_failed, unlink_sent=unlink_sent, raise_exception=raise_exception)
             # auto-commit if asked except in testing mode
@@ -101,7 +105,7 @@ class SmsSms(models.Model):
                 self._cr.commit()
 
     def resend_failed(self):
-        sms_to_send = self.filtered(lambda sms: sms.state == 'error')
+        sms_to_send = self.filtered(lambda sms: sms.state == 'error' and not sms.to_delete)
         sms_to_send.state = 'outgoing'
         notification_title = _('Warning')
         notification_type = 'danger'
@@ -135,7 +139,7 @@ class SmsSms(models.Model):
        :param list ids: optional list of emails ids to send. If passed no search
          is performed, and these ids are used instead.
         """
-        domain = [('state', '=', 'outgoing')]
+        domain = [('state', '=', 'outgoing'), ('to_delete', '!=', True)]
 
         filtered_ids = self.search(domain, limit=10000).ids  # TDE note: arbitrary limit we might have to update
         if ids:
@@ -177,30 +181,30 @@ class SmsSms(models.Model):
 
         results_uuids = [result['uuid'] for result in results]
         all_sms_sudo = self.env['sms.sms'].sudo().search([('uuid', 'in', results_uuids)]).with_context(sms_skip_msg_notification=True)
-        mail_message_ids_sudo = all_sms_sudo.mail_message_id
 
         for iap_state, results_group in tools.groupby(results, key=lambda result: result['state']):
             sms_sudo = all_sms_sudo.filtered(lambda s: s.uuid in {result['uuid'] for result in results_group})
             if success_state := self.IAP_TO_SMS_STATE_SUCCESS.get(iap_state):
                 sms_sudo.sms_tracker_id._action_update_from_sms_state(success_state)
-                if unlink_sent:
-                    sms_sudo.unlink()
-                else:
-                    sms_sudo.write({'state': success_state, 'failure_type': False})
+                to_delete = {'to_delete': True} if unlink_sent else {}
+                sms_sudo.write({'state': success_state, 'failure_type': False, **to_delete})
             else:
                 failure_type = self.IAP_TO_SMS_FAILURE_TYPE.get(iap_state, 'unknown')
                 if failure_type != 'unknown':
                     sms_sudo.sms_tracker_id._action_update_from_sms_state('error', failure_type=failure_type)
                 else:
                     sms_sudo.sms_tracker_id._action_update_from_provider_error(iap_state)
-                if unlink_failed:
-                    sms_sudo.unlink()
-                else:
-                    sms_sudo.write({'state': 'error', 'failure_type': failure_type})
+                to_delete = {'to_delete': True} if unlink_failed else {}
+                sms_sudo.write({'state': 'error', 'failure_type': failure_type, **to_delete})
 
-        mail_message_ids_sudo._notify_message_notification_update()
+        all_sms_sudo.mail_message_id._notify_message_notification_update()
 
     def _update_sms_state_and_trackers(self, new_state, failure_type=None):
         """Update sms state update and related tracking records (notifications, traces)."""
         self.write({'state': new_state, 'failure_type': failure_type})
         self.sms_tracker_id._action_update_from_sms_state(new_state, failure_type=failure_type)
+
+    @api.autovacuum
+    def _gc_device(self):
+        self._cr.execute("DELETE FROM sms_sms WHERE to_delete = TRUE")
+        _logger.info("GC'd %d sms marked for deletion", self._cr.rowcount)
diff --git a/addons/sms/tests/common.py b/addons/sms/tests/common.py
index 11c28f16a4a..e86894d09de 100644
--- a/addons/sms/tests/common.py
+++ b/addons/sms/tests/common.py
@@ -138,10 +138,6 @@ class SMSCase(MockSMS):
             raise NotImplementedError()
         return sms
 
-    def assertNoSMS(self):
-        """ Check no sms persisted during mock. """
-        self.assertEqual(len(self._new_sms.exists()), 0)
-
     def assertSMSIapSent(self, numbers, content=None):
         """ Check sent SMS. Order is not checked. Each number should have received
         the same content. Useful to check batch sending.
diff --git a/addons/sms/views/sms_sms_views.xml b/addons/sms/views/sms_sms_views.xml
index 59b5c84447b..82cd23459cb 100644
--- a/addons/sms/views/sms_sms_views.xml
+++ b/addons/sms/views/sms_sms_views.xml
@@ -6,7 +6,8 @@
         <field name="arch" type="xml">
             <form string="SMS">
                 <header>
-                    <button name="send" string="Send Now" type="object" invisible="state != 'outgoing'" class="oe_highlight"/>
+                    <field name="to_delete" invisible="1"/>
+                    <button name="send" string="Send Now" type="object" invisible="state != 'outgoing' or to_delete" class="oe_highlight"/>
                     <button name="action_set_outgoing" string="Retry" type="object" invisible="state not in ('error', 'canceled')"/>
                     <button name="action_set_canceled" string="Cancel" type="object" invisible="state not in ('error', 'outgoing')"/>
                     <field name="state" widget="statusbar" statusbar_visible="outgoing,sent,error,canceled"/>
@@ -62,6 +63,7 @@
         <field name="name">SMS</field>
         <field name="res_model">sms.sms</field>
         <field name="view_mode">tree,form</field>
+        <field name="domain">[('to_delete', '!=', True)]</field>
     </record>
 
     <menuitem id="sms_sms_menu"
diff --git a/addons/test_mail_sms/tests/test_sms_composer.py b/addons/test_mail_sms/tests/test_sms_composer.py
index 48613089ac6..989fe7c06e5 100644
--- a/addons/test_mail_sms/tests/test_sms_composer.py
+++ b/addons/test_mail_sms/tests/test_sms_composer.py
@@ -46,9 +46,8 @@ class TestSMSComposerComment(SMSCommon, TestSMSRecipients):
             with self.mockSMSGateway(sms_allow_unlink=True):
                 composer._action_send_sms()
 
-        # sms.sms was deleted as successfully sent
-        self.assertNoSMS()
-        self.assertSMSIapSent(self.random_numbers_san, self._test_body)
+        for number in self.random_numbers_san:
+            self.assertSMS(self.env['res.partner'], number, 'pending', content=self._test_body, fields_values={'to_delete': True})
 
     def test_composer_comment_default(self):
         with self.with_user('employee'):
@@ -262,9 +261,8 @@ class TestSMSComposerComment(SMSCommon, TestSMSRecipients):
             with self.mockSMSGateway(sms_allow_unlink=True):
                 composer._action_send_sms()
 
-        # sms.sms was deleted as successfully sent
-        self.assertNoSMS()
-        self.assertSMSIapSent(self.random_numbers_san, self._test_body)
+        for number in self.random_numbers_san:
+            self.assertSMS(self.env['res.partner'], number, 'pending', content=self._test_body, fields_values={'to_delete': True})
 
     def test_composer_sending_with_no_number_field(self):
         test_record = self.env['mail.test.sms.partner'].create({'name': 'Test'})
diff --git a/addons/test_mail_sms/tests/test_sms_management.py b/addons/test_mail_sms/tests/test_sms_management.py
index 7b7a472a9e0..ca9e74fd735 100644
--- a/addons/test_mail_sms/tests/test_sms_management.py
+++ b/addons/test_mail_sms/tests/test_sms_management.py
@@ -32,7 +32,7 @@ class TestSMSActionsCommon(SMSCommon, TestSMSRecipients):
             'author_id': cls.msg.author_id.id,
             'mail_message_id': cls.msg.id,
             'res_partner_id': cls.partner_1.id,
-            'sms_id': cls.sms_p1.id,
+            'sms_id_int': cls.sms_p1.id,
             'sms_number': cls.partner_1.mobile,
             'sms_tracker_ids': [Command.create({'sms_uuid': cls.sms_p1.uuid})],
             'notification_type': 'sms',
@@ -52,7 +52,7 @@ class TestSMSActionsCommon(SMSCommon, TestSMSRecipients):
             'author_id': cls.msg.author_id.id,
             'mail_message_id': cls.msg.id,
             'res_partner_id': cls.partner_2.id,
-            'sms_id': cls.sms_p2.id,
+            'sms_id_int': cls.sms_p2.id,
             'sms_number': cls.partner_2.mobile,
             'sms_tracker_ids': [Command.create({'sms_uuid': cls.sms_p2.uuid})],
             'notification_type': 'sms',
diff --git a/addons/test_mail_sms/tests/test_sms_performance.py b/addons/test_mail_sms/tests/test_sms_performance.py
index 3c6872cb058..061caba1048 100644
--- a/addons/test_mail_sms/tests/test_sms_performance.py
+++ b/addons/test_mail_sms/tests/test_sms_performance.py
@@ -117,7 +117,7 @@ class TestSMSMassPerformance(BaseMailPerformance, sms_common.MockSMS):
             'mass_keep_log': False,
         })
 
-        with self.mockSMSGateway(sms_allow_unlink=True), self.assertQueryCount(employee=55):
+        with self.mockSMSGateway(sms_allow_unlink=True), self.assertQueryCount(employee=54):
             composer.action_send_sms()
 
     @mute_logger('odoo.addons.sms.models.sms_sms')
@@ -133,5 +133,5 @@ class TestSMSMassPerformance(BaseMailPerformance, sms_common.MockSMS):
             'mass_keep_log': True,
         })
 
-        with self.mockSMSGateway(sms_allow_unlink=True), self.assertQueryCount(employee=58):
+        with self.mockSMSGateway(sms_allow_unlink=True), self.assertQueryCount(employee=57):
             composer.action_send_sms()
diff --git a/addons/test_mail_sms/tests/test_sms_sms.py b/addons/test_mail_sms/tests/test_sms_sms.py
index 06103570f4d..cfa508ce2c1 100644
--- a/addons/test_mail_sms/tests/test_sms_sms.py
+++ b/addons/test_mail_sms/tests/test_sms_sms.py
@@ -46,7 +46,7 @@ class TestSMSPost(SMSCommon, MockLinkTracker):
     def test_sms_send_delete_all(self):
         with self.mockSMSGateway(sms_allow_unlink=True, sim_error='jsonrpc_exception'):
             self.env['sms.sms'].browse(self.sms_all.ids).send(unlink_failed=True, unlink_sent=True, raise_exception=False)
-        self.assertFalse(len(self.sms_all.exists()))
+        self.assertFalse(len(self.sms_all.exists().filtered(lambda s: not s.to_delete)))
 
     def test_sms_send_delete_default(self):
         """ Test default send behavior: keep failed SMS, remove sent. """
@@ -57,7 +57,7 @@ class TestSMSPost(SMSCommon, MockLinkTracker):
                 '+32456000044': 'unregistered',
         }):
             self.env['sms.sms'].browse(self.sms_all.ids).send(raise_exception=False)
-        remaining = self.sms_all.exists()
+        remaining = self.sms_all.exists().filtered(lambda s: not s.to_delete)
         self.assertEqual(len(remaining), 4)
         self.assertEqual(set(remaining.mapped('state')), {'error'})
 
@@ -67,7 +67,7 @@ class TestSMSPost(SMSCommon, MockLinkTracker):
                 '+32456000022': 'wrong_number_format',
         }):
             self.env['sms.sms'].browse(self.sms_all.ids).send(unlink_failed=True, unlink_sent=False, raise_exception=False)
-        remaining = self.sms_all.exists()
+        remaining = self.sms_all.exists().filtered(lambda s: not s.to_delete)
         self.assertEqual(len(remaining), 8)
         self.assertEqual(set(remaining.mapped('state')), {'pending'})
 
@@ -89,7 +89,7 @@ class TestSMSPost(SMSCommon, MockLinkTracker):
                 '+32456000022': 'wrong_number_format',
         }):
             self.env['sms.sms'].browse(self.sms_all.ids).send(unlink_failed=False, unlink_sent=True, raise_exception=False)
-        remaining = self.sms_all.exists()
+        remaining = self.sms_all.exists().filtered(lambda s: not s.to_delete)
         self.assertEqual(len(remaining), 2)
         self.assertEqual(set(remaining.mapped('state')), {'error'})