1 files changed, 2 insertions, 0 deletions
diff --git a/Lib/bdb.py b/Lib/bdb.py
index 7f9b095..0f3eec6 100644
--- a/Lib/bdb.py
+++ b/Lib/bdb.py
@@ -574,6 +574,8 @@ class Bdb:
             line = linecache.getline(filename, lineno, frame.f_globals)
             if line:
                 s += lprefix + line.strip()
+        else:
+            s += f'{lprefix}Warning: lineno is None'
         return s
 
     # The following methods can be called by clients to use