assertion message was dropped

diff --git a/Lib/distutils/extension.py b/Lib/distutils/extension.py
index 98b841face2c8e0cc500bbc273fc92da87923a28..53ca8fd0c579f2d8fd58f0bb79d3ad66c37a4ffb 100644 (file)
--- a/Lib/distutils/extension.py
+++ b/Lib/distutils/extension.py
@@ -103,7 +103,7 @@ class Extension:
                   optional=None,
                   **kw                      # To catch unknown keywords
                  ):
-        assert isinstance(name, str)
+        assert isinstance(name, str), "'name' must be a string"
         assert (isinstance(sources, list) and
                 all(isinstance(v, str) for v in sources)), \
                 "'sources' must be a list of strings"