--- a/builtin/ulimit.c	2020-02-03 17:43:24.961064732 +0300
+++ b/builtin/ulimit.c	2020-02-03 17:46:08.082450486 +0300
@@ -14,6 +14,9 @@
 static const char ulimit_usage[] = "usage: ulimit [-f] [blocks]\n";
 
 int builtin_ulimit(struct mrsh_state *state, int argc, char *argv[]) {
+	fprintf(stderr, "unimplemented\n");
+	return 1;
+/*
 	mrsh_optind = 0;
 	int opt;
 	while ((opt = mrsh_getopt(argc, argv, ":f")) != -1) {
@@ -58,4 +61,5 @@
 	}
 
 	return 0;
+*/
 }