I ran into the following error message:
# futility gbb --set --flash --flags=0x39 INFO: write_system_firmware: flashrom -w <IMAGE> -p host -i GBB FAILED at 0x003f5000! Expected=0xff, Found=0x24, failed byte count from 0x003f5000-0x003f5fff: 0xffd ERASE_FAILED FAILED! Uh oh. Erase/write failed. Your flash chip is in an unknown state. Please report this to the mailing list at email@example.com or on IRC (see https://www.flashrom.org/Contact for details), thanks!
Is that enough information? Is there something else that I can share?