+PYTHON=python
+
+TAPFILTER=cat
+ifeq (,$(command -v tapview))
+ TAPFILTER=tapview
+else
+ ifeq (,$(command -v tappy))
+ TAPFILTER=tappy
+ endif
+endif
+
+all:
+ @echo "With Python 2:"
+ @$(MAKE) -e PYTHON=python2 regress | $(TAPFILTER)
+ @echo "With Python 3:"
+ @$(MAKE) -e PYTHON=python3 regress | $(TAPFILTER)