Migrate to 6.0

locale/es.po

@@ -2,6 +2,10 @@
 msgid ""
 msgstr "Content-Type: text/plain; charset=utf-8\n"
 
+msgctxt "model:ir.message,text:msg_stock_location_state_date_location_uniq"
+msgid "Combination of Date and Location must be unique."
+msgstr "Combinación de fecha y ubicación debe ser única."
+
 msgctxt "field:stock.location,states:"
 msgid "History State"
 msgstr "Historial de estados"

location.py

@@ -9,7 +9,6 @@ from trytond.model import ModelSQL, ModelView, fields, Unique
 from trytond.pool import PoolMeta, Pool
 from trytond.pyson import Eval, Or, If
 from trytond.transaction import Transaction
-from trytond import backend
 from itertools import groupby
 
 STATES = [
@@ -333,7 +332,8 @@ class LocationState(ModelSQL, ModelView):
         t = cls.__table__()
         cls._sql_constraints += [
             ('date_location_uniq', Unique(t, t.date, t.location),
-                'Combination of Date and Location must be unique.'),
+                'stock_location_history_state.'
+                'msg_stock_location_state_date_location_uniq'),
         ]
 
     @classmethod

message.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<!-- The COPYRIGHT file at the top level of this repository contains the full
+     copyright notices and license terms. -->
+<tryton>
+    <data grouped="1">
+		<!-- stock.location.state -->
+        <record model="ir.message" id="msg_stock_location_state_date_location_uniq">
+            <field name="text">Combination of Date and Location must be unique.</field>
+        </record>
+    </data>
+</tryton>

tryton.cfg

@@ -11,3 +11,4 @@ extras_depend:
 
 xml:
   location.xml
+  message.xml