fix obvious error:
common.c:247:5: warning: format '%s' expects a matching 'char *' argument [-Wformat=]

--- a/builtins/common.c
+++ b/builtins/common.c
@@ -244,7 +244,7 @@
      char *s;
 {
   if (s)
-    builtin_error ("%s: no job control");
+    builtin_error ("%s: no job control", s);
   else
     builtin_error ("no job control");
 }