Define dummy functions to silence warnings

util/vars.sh

@@ -9,3 +9,27 @@ TARGET="$1"
 VARIANT="${2:-gpl}"
 REPO="${DOCKER_REPO:-btbn/ffmpeg-builder}"
 IMAGE="$REPO:$TARGET-$VARIANT"
+
+ffbuild_configure() {
+    return 0
+}
+
+ffbuild_unconfigure() {
+    return 0
+}
+
+ffbuild_cflags() {
+    return 0
+}
+
+ffbuild_uncflags() {
+    return 0
+}
+
+ffbuild_ldflags() {
+    return 0
+}
+
+ffbuild_unldflags() {
+    return 0
+}