diff --git a/Makefile b/Makefile
index 45165145b..f57eb7e93 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,4 @@
 # Saner makefile
-MAKEFLAGS += --no-builtin-rules
 BASE_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
 TOOLS_DIR := $(BASE_DIR)/tools
 
diff --git a/external/R b/external/R
new file mode 160000
index 000000000..02cb3ab35
--- /dev/null
+++ b/external/R
@@ -0,0 +1 @@
+Subproject commit 02cb3ab35337e154a3d200a2dc6f54a307bc3ba5
diff --git a/tools/build-gnur.sh b/tools/build-gnur.sh
index 00f1f35d0..d83a7e094 100755
--- a/tools/build-gnur.sh
+++ b/tools/build-gnur.sh
@@ -13,12 +13,21 @@ if [ ! -d "$BASE_DIR" ]; then
 	exit 1
 fi
 
-if [[ "$1" == "--debug" ]]; then
-	export CFLAGS="-ggdb3 -O0"
-	export CXXFLAGS="-ggdb3 -O0"
-	export CPPFLAGS="-ggdb3 -O0"
-	echo "Building a debug version of R"
-fi
+while [[ $# -gt 0 ]]; do
+	case $1 in
+	-d | --debug)
+		export CFLAGS="-ggdb3 -O0"
+		export CXXFLAGS="-ggdb3 -O0"
+		export CPPFLAGS="-ggdb3 -O0"
+		echo "Building a debug version of R"
+		shift
+		;;
+	*)
+		echo "Unknown option $1"
+		exit 1
+		;;
+	esac
+done
 
 if [[ "$OSTYPE" == "darwin"* ]]; then
 	USING_OSX=1