Pressing buttons apparently has something to do with it... I found the text "Holding down Boot and then pressing EN initiates Firmware Download mode for downloading firmware through the serial port." and when I tried that, sure enough it worked! The board is now happily sitting there blinking for me...

Maybe. I *did* find the python file referenced, it was in the directory ".arduino", which I hadn't looked in before. I did make the change suggested in that other thread, commenting out that one line, and now I get different errors: Arduino: 1.8.13 (Linux), Board: "DOIT ESP32 DEVKIT V1, 80MHz, 92160...

A while back I bought some of these: https://www.banggood.com/Geekcreit-ESP32-WiFi+bluetooth-Development-Board-Ultra-Low-Power-Consumption-Dual-Cores-Pins-Unsoldered-p-1214159.html?rmmds=myorder&cur_warehouse=CN which as far as I can tell are a clone of this board: https://github.com/SmartArduino/SZ...