Check out the fixed avrgirl-arduino package

[flaki]

Initially, avrgirl-arduino had quite a few timing-related issues with the Arduboy, which resulted in the creation a simplified script based on the original to power Clouduboy's Flasher.

@noopkat since then has updated the library, it would worth it to check the fixes and remove the fork, or make the changes upstream so we can somewhat simplify the source.