diff -r 4f7845be9e23 Modules/spwdmodule.c
--- a/Modules/spwdmodule.c	Mon Aug 19 23:31:18 2013 +0200
+++ b/Modules/spwdmodule.c	Tue Aug 20 12:11:03 2013 +0800
@@ -122,7 +122,12 @@
     if (PyBytes_AsStringAndSize(bytes, &name, NULL) == -1)
         goto out;
     if ((p = getspnam(name)) == NULL) {
-        PyErr_SetString(PyExc_KeyError, "getspnam(): name not found");
+        if (errno==EACCES) {
+            PyErr_SetString(PyExc_OSError, "getspnam(): the caller does not "
+                "have permission to access the shadow password file");
+        } else {
+            PyErr_SetString(PyExc_KeyError, "getspnam(): name not found");
+        }
         goto out;
     }
     retval = mkspent(p);