-DEB_DEPENDS += cmake ninja-build uuid-dev python3-jsonschema python3-yaml yamllint
-ifeq ($(OS_VERSION_ID),14.04)
+DEB_DEPENDS += cmake ninja-build uuid-dev python3-jsonschema python3-yaml
+DEB_DEPENDS += python3-venv # ensurepip
+DEB_DEPENDS += python3-dev # needed for python3 -m pip install psutil
+# python3.6 on 16.04 requires python36-dev
+
+LIBFFI=libffi6 # works on all but 20.04
+
+ifeq ($(OS_VERSION_ID),18.04)
+ DEB_DEPENDS += python-dev python-all python-pip python-virtualenv
+ DEB_DEPENDS += libssl-dev
+ DEB_DEPENDS += clang-9
+else ifeq ($(OS_VERSION_ID),20.04)
+ DEB_DEPENDS += python3-virtualenv