argc = parse_options(argc, argv, builtin_config_options, builtin_config_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
+ if (use_global_config + use_system_config + !!given_config_file > 1) {
+ error("only one config file at a time.");
+ usage_with_options(builtin_config_usage, builtin_config_options);
+ }
+
if (use_global_config) {
char *home = getenv("HOME");
if (home) {