It was discovered that FreeBSD doesn't setup alias from default
Python version neither to python3 nor python, and thus the configure
step would fail to find working python installation.
testsetup='try: from distutils.core import setup
except: exit(1)'
-default_with_python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
+default_with_python="python python3 python3.8 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
testsetup='try: from distutils.core import setup
except: exit(1)'
-default_with_python="python python3 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
+default_with_python="python python3 python3.8 python3.7 python3.6 python3.5 python3.4 python3.3 python3.2 python2 python2.7"
AC_ARG_VAR([PYTHON], [path to python executable])