diff -ur otp-OTP-21.0.5.orig/otp_build otp-OTP-21.0.5/otp_build
--- otp-OTP-21.0.5.orig/otp_build	2018-08-10 19:02:51.000000000 +0200
+++ otp-OTP-21.0.5/otp_build	2018-08-15 23:44:59.417191209 +0200
@@ -1343,7 +1343,9 @@
 		do_lazy_configure "$@";
 		do_boot;;
 	autoconf)
-		do_autoconf;;
+		create_lib_configure_in
+		distribute_config_helpers
+		;;
 	configure)
 		shift;
 		do_configure "$@";;