thx @fpilger, fantastic to see another Py3 ready application. It&#x27;s clear now. One way to avoid this is either give a install write up an installation guide [0] that explicitly mentions the python version and dependencies.<p>This is one of the first questions I ask, &quot;is this code Python3 ready?&quot;, so I look at the install requirements first. Maybe I&#x27;m an edge case. A short cut might be just to say in big words, Python3 ready.<p>[0] For example this PIL fork, Pillow (python3) <a href="https:&#x2F;&#x2F;pillow.readthedocs.org&#x2F;en&#x2F;latest&#x2F;installation.html" rel="nofollow">https:&#x2F;&#x2F;pillow.readthedocs.org&#x2F;en&#x2F;latest&#x2F;installation.html</a>