Adding custom platform to Platformio

PlatformIO IDE
1

Hi,
I am trying to use a custom build for a platformio. Specifically, I am able to use the arduino-esp32 platform to do development. But there is another tree on the main line(GitHub - espressif/arduino-esp32: Arduino core for the ESP32), that I would like to use: https://github.com/espressif/arduino-esp32/tree/stickbreaker-i2c .
How do I do this ?

Thanks.

2

Were you able to figure this out?