Index: build_file.epp
===================================================================
--- build_file.epp  (revision 60595)
+++ build_file.epp  (working copy)
@@ -119,7 +119,15 @@
                if (argv >= end_args)
                    sw_bad = true;
                else
+                {
                    copy_terminate(db_file, *argv++, MAXPATHLEN);
+
+                    FILE *f = fopen(db_file, "rb");
+                    if (!f)
+                       exit(FINI_ERROR);
+                    else
+                        fclose(f);
+                }
                break;

            case 'F':