[stonebig]

as Windows-10 didn't like character '\u2295'

[petercorke]

Thank you for your interest in RTB, and for catching this — a good, simple fix.

This exact bug survived a move since you filed this: dotfile()'s missing encoding="utf-8" moved from ERobot.py (2021) to BaseRobot.py along the way, carrying the bug with it. Just fixed directly (crediting your original catch) in #586, as part of adding a graph() method alongside dotfile().

Closing as fixed, but thank you for flagging it four years ago — it was still there.