diff --git a/runbot_populate/demo/runbot_demo.xml b/runbot_populate/demo/runbot_demo.xml
index da55fc03..203213cb 100644
--- a/runbot_populate/demo/runbot_demo.xml
+++ b/runbot_populate/demo/runbot_demo.xml
@@ -55,6 +55,10 @@
         <field name="repo_id" ref="repo_runbot"/>
     </record>
 
+    <record id="version_16" model="runbot.version">
+        <field name="name">16.0</field>
+    </record>
+
     <!-- BUNDLES -->
     <record id="bundle_16_1" model="runbot.bundle">
         <field name="name">saas-16.1</field>
@@ -146,7 +150,6 @@
         <field name="ci_context"/>        
     </record>
 
-
     <record id="runbot_build_config_linting" model="runbot.build.config">
         <field name="name">Linting</field>
     </record>
@@ -154,6 +157,47 @@
         <field name="name">Security</field>
     </record>
 
+    <record id="runbot_build_config_split" model="runbot.build.config">
+        <field name="name">Split</field>
+    </record>
+
+    <record id="runbot_build_config_post_install" model="runbot.build.config">
+        <field name="name">Post install</field>
+    </record>
+
+    <record id="main_host" model="runbot.host">
+        <field name="name">main host</field>
+    </record>
+
+    <record id="build_base_params" model="runbot.build.params">
+        <field name="config_id" ref="runbot_build_config_split"/>
+        <field name="version_id" ref="version_16"/>
+        <field name="project_id" ref="project_runbot"/>
+    </record>
+
+    <record id="build_base" model="runbot.build">
+        <field name="params_id" ref="build_base_params"/>
+        <field name="host">main host</field>
+    </record>
+
+    <record id="build_child_params" model="runbot.build.params">
+        <field name="config_id" ref="runbot_build_config_post_install"/>
+        <field name="version_id" ref="version_16"/>
+        <field name="project_id" ref="project_runbot"/>
+    </record>
+
+    <record id="build_child1" model="runbot.build">
+        <field name="params_id" ref="build_child_params"/>
+        <field name="parent_id" ref="build_base"/>
+        <field name="host">main host</field>
+    </record>
+
+    <record id="build_child2" model="runbot.build">
+        <field name="params_id" ref="build_child_params"/>
+        <field name="parent_id" ref="build_base"/>
+        <field name="host">main host</field>
+    </record>
+    
     <function model="runbot.runbot" name="_create_demo_data">
     </function>
     
diff --git a/runbot_populate/tests/__init__.py b/runbot_populate/tests/__init__.py
new file mode 100644
index 00000000..173715a4
--- /dev/null
+++ b/runbot_populate/tests/__init__.py
@@ -0,0 +1 @@
+from . import test_concurrency
diff --git a/runbot_populate/tests/test_concurrency.py b/runbot_populate/tests/test_concurrency.py
new file mode 100644
index 00000000..b5b1f7ab
--- /dev/null
+++ b/runbot_populate/tests/test_concurrency.py
@@ -0,0 +1,55 @@
+from odoo import api, SUPERUSER_ID
+from odoo.tests import TransactionCase
+from unittest.mock import patch
+
+
+class TestConcurrency(TransactionCase):
+    def test_local_status_update(self):
+        """
+        This test ensures that a parent build global state will eventually be updated
+        even if updated concurrenctly in 2 different transactions, without transaction error
+        """
+        with self.registry.cursor() as cr0:
+            env0 = api.Environment(cr0, SUPERUSER_ID, {})
+            host = env0.ref('runbot_populate.main_host')
+            host._process_messages()  # ensure queue is empty
+            parent_build = env0.ref('runbot_populate.build_base')
+            build_child1 = env0.ref('runbot_populate.build_child1')
+            build_child2 = env0.ref('runbot_populate.build_child2')
+            parent_build.local_state = 'done'
+            self.assertEqual(host.host_message_ids.mapped('message'), [])
+            build_child1.local_state = 'testing'
+            build_child2.local_state = 'testing'
+            self.assertEqual(host.host_message_ids.mapped('message'), ['global_updated', 'global_updated'])
+            self.assertEqual(host.host_message_ids.build_id, parent_build)
+            host._process_messages()
+            self.assertEqual(parent_build.global_state, 'waiting')
+            env0.cr.commit()  # youplahé
+
+            with self.registry.cursor() as cr1:
+                env1 = api.Environment(cr1, SUPERUSER_ID, {})
+                with self.registry.cursor() as cr2:
+                    env2 = api.Environment(cr2, SUPERUSER_ID, {})
+                    build_child_cr1 = env1['runbot.build'].browse(build_child1.id)
+                    build_child_cr2 = env2['runbot.build'].browse(build_child2.id)
+                    self.assertEqual(build_child_cr1.parent_id.global_state, 'waiting')
+                    self.assertEqual(build_child_cr1.parent_id.children_ids.mapped('local_state'), ['testing', 'testing'])
+                    self.assertEqual(build_child_cr2.parent_id.global_state, 'waiting')
+                    self.assertEqual(build_child_cr2.parent_id.children_ids.mapped('local_state'), ['testing', 'testing'])
+                    build_child_cr1.local_state = 'done'
+                    build_child_cr2.local_state = 'done'
+                    # from the point of view of each transaction, the other one local_state didn't changed
+                    self.assertEqual(build_child_cr1.parent_id.children_ids.mapped('local_state'), ['testing', 'done'])
+                    self.assertEqual(build_child_cr2.parent_id.global_state, 'waiting')
+                    self.assertEqual(build_child_cr2.parent_id.children_ids.mapped('local_state'), ['done', 'testing'])
+                    env1.cr.commit()
+                    env2.cr.commit()
+                    env0.cr.commit()  # not usefull just to ensure we have efefct of other transactions
+                    env0.cache.invalidate()
+                    self.assertEqual(parent_build.children_ids.mapped('local_state'), ['done', 'done'])
+                    self.assertEqual(parent_build.children_ids.mapped('global_state'), ['done', 'done'])
+                    self.assertEqual(host.host_message_ids.mapped('message'), ['global_updated', 'global_updated'])
+                    self.assertEqual(host.host_message_ids.build_id, parent_build)
+                    # at this point, this assertion is true, but not expected : self.assertEqual(parent_build.global_state, 'waiting')
+                    host._process_messages()
+                    self.assertEqual(parent_build.global_state, 'done')