posix_getlogin():  Be more cautious about interpreting a NULL from
                   getlogin() -- it is not clear that a NULL is always
                   an error.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 2ddcebc..4a991f9 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1914,7 +1914,7 @@
                 posix_error();
             else
                 PyErr_SetString(PyExc_OSError,
-                                "unexpected NULL from getlogin()");
+                                "unable to determine login name");
         }
         else
             result = PyString_FromString(name);