Add PDB on exception debug tool and config setting

apps/common/__init__.py

@@ -22,6 +22,10 @@ from .utils import validate_path
 from .links import (password_change_view, current_user_details,
     current_user_edit, about_view, license_view, admin_site, sentry)
 from .models import AutoAdminSingleton
+from .debug import insert_pdb_exception_hook
+
+if getattr(settings, 'DEBUG_ON_EXCEPTION', False):
+    insert_import_hook()
 
 bind_links(['about_view', 'license_view'], [about_view, license_view], menu_name='secondary_menu')
 bind_links(['current_user_details', 'current_user_edit', 'password_change_view'], [current_user_details, current_user_edit, password_change_view], menu_name='secondary_menu')

apps/common/debug.py

@@ -0,0 +1,16 @@
+import sys, pdb
+
+previous_except_hook = None
+
+
+def except_hook(exctype, value, traceback):
+    if previous_except_hook:
+        previous_except_hook(exctype, value, traceback)
+
+    pdb.post_mortem(traceback)
+
+
+def insert_pdb_exception_hook():
+    previous_except_hook = sys.excepthook
+    sys.excepthook = except_hook
+