must I use python 2.x to build?

[jokerleon]

RENDER WARNING: texture bound to texture unit 0 is not renderable. It maybe non-power-of-2 and have incompatible texture filtering.
when I use phython3.7 to run build.py, then use the glfx.js just built with demo, it comes out this warning and the canvas can't render in chrome, but if I use "http://evanw.github.com/glfx.js/glfx.js", is works.
does anyone came up with the same problem?
I assume maybe I should use phython 2.x, does is matters?