@@ -6,4 +6,16 @@
 	test "${!var}" == "" || return 0
 	say "we were not able to detect a default value for the configuration variable \$$var. please set this variable to $2 and try again."
 	exit 1
 }
+
+test "$out" = "" && {
+	say "\$out environment variable must be set to your build directory - are you running this script by hand? run ./build.sh in the root directory instead!"
+	exit 2
+}
+
+reqpack() {
+	if ! has "$1"; then
+		say "to $2 for libk, install the $1 package and try again"
+		exit 3
+	fi
+}