4 files changed, 90 insertions, 0 deletions
diff --git a/django/core/compat_checks/__init__.py b/django/core/compat_checks/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/django/core/compat_checks/__init__.py
diff --git a/django/core/compat_checks/base.py b/django/core/compat_checks/base.py
new file mode 100644
index 0000000000..b3d47a617c
--- /dev/null
+++ b/django/core/compat_checks/base.py
@@ -0,0 +1,39 @@
+from __future__ import unicode_literals
+import warnings
+
+from django.core.compat_checks import django_1_6_0
+
+
+COMPAT_CHECKS = [
+    # Add new modules at the top, so we keep things in descending order.
+    # After two-three minor releases, old versions should get dropped.
+    django_1_6_0,
+]
+
+
+def check_compatibility():
+    """
+    Runs through compatibility checks to warn the user with an existing install
+    about changes in an up-to-date Django.
+
+    Modules should be located in ``django.core.compat_checks`` (typically one
+    per release of Django) & must have a ``run_checks`` function that runs
+    all the checks.
+
+    Returns a list of informational messages about incompatibilities.
+    """
+    messages = []
+
+    for check_module in COMPAT_CHECKS:
+        check = getattr(check_module, u'run_checks', None)
+
+        if check is None:
+            warnings.warn(
+                u"The '%s' module lacks a " % check_module.__name__ +
+                u"'run_checks' method, which is needed to verify compatibility."
+            )
+            continue
+
+        messages.extend(check())
+
+    return messages
diff --git a/django/core/compat_checks/django_1_6_0.py b/django/core/compat_checks/django_1_6_0.py
new file mode 100644
index 0000000000..53fe150cab
--- /dev/null
+++ b/django/core/compat_checks/django_1_6_0.py
@@ -0,0 +1,37 @@
+from __future__ import unicode_literals
+
+
+def check_test_runner():
+    """
+    Checks if the user has *not* overridden the ``TEST_RUNNER`` setting &
+    warns them about the default behavior changes.
+
+    If the user has overridden that setting, we presume they know what they're
+    doing & avoid generating a message.
+    """
+    from django.conf import settings
+    new_default = u'django.test.runner.DiscoverRunner'
+    test_runner_setting = getattr(settings, u'TEST_RUNNER', new_default)
+
+    if test_runner_setting == new_default:
+        message = [
+            u"You have not explicitly set 'TEST_RUNNER'. In Django 1.6,",
+            u"there is a new test runner ('%s')" % new_default,
+            u"by default. You should ensure your tests are still all",
+            u"running & behaving as expected. See",
+            u"https://docs.djangoproject.com/en/dev/releases/1.6/#discovery-of-tests-in-any-test-module",
+            u"for more information.",
+        ]
+        return u' '.join(message)
+
+
+def run_checks():
+    """
+    Required by the ``checksetup`` management command, this returns a list of
+    messages from all the relevant check functions for this version of Django.
+    """
+    checks = [
+        check_test_runner()
+    ]
+    # Filter out the ``None`` or empty strings.
+    return [output for output in checks if output]
diff --git a/django/core/management/commands/checksetup.py b/django/core/management/commands/checksetup.py
new file mode 100644
index 0000000000..35082b6093
--- /dev/null
+++ b/django/core/management/commands/checksetup.py
@@ -0,0 +1,14 @@
+from __future__ import unicode_literals
+import warnings
+
+from django.core.compat_checks.base import check_compatibility
+from django.core.management.base import NoArgsCommand
+
+
+class Command(NoArgsCommand):
+    help = u"Checks your configuration's compatibility with this version " + \
+           u"of Django."
+
+    def handle_noargs(self, **options):
+        for message in check_compatibility():
+            warnings.warn(message)