--- a/Makefile	Fri Mar 12 23:04:56 2021 +0100
+++ b/Makefile	Wed Mar 10 13:53:31 2021 +0100
@@ -68,6 +68,9 @@
 build:
 	$(PYTHON) setup.py $(PURE) build $(COMPILERFLAG)
 
+build-chg:
+	make -C contrib/chg
+
 wheel:
 	FORCE_SETUPTOOLS=1 $(PYTHON) setup.py $(PURE) bdist_wheel $(COMPILERFLAG)