[1.7.x] Fixed #8033 -- Explained app registry error during translation setup

Thanks Tim Graham and Aymeric Augustin for the review.
Backport of 9618d68b34 from master.

1 files changed, 9 insertions, 1 deletions

diff --git a/django/utils/translation/trans_real.py b/django/utils/translation/trans_real.py
index 0fe5ebd7ae..46f38042c1 100644
--- a/django/utils/translation/trans_real.py
+++ b/django/utils/translation/trans_real.py
@@ -10,6 +10,7 @@ from threading import local
 import warnings
 
 from django.apps import apps
+from django.core.exceptions import AppRegistryNotReady
 from django.dispatch import receiver
 from django.test.signals import setting_changed
 from django.utils.deprecation import RemovedInDjango19Warning
@@ -181,7 +182,14 @@ def translation(language):
                     res.merge(t)
             return res
 
-        for app_config in reversed(list(apps.get_app_configs())):
+        try:
+            app_configs = reversed(list(apps.get_app_configs()))
+        except AppRegistryNotReady:
+            raise AppRegistryNotReady(
+                "The translation infrastructure cannot be initialized before the "
+                "apps registry is ready. Check that you don't make non-lazy "
+                "gettext calls at import time.")
+        for app_config in app_configs:
             apppath = os.path.join(app_config.path, 'locale')
             if os.path.isdir(apppath):
                 res = _merge(apppath)