How to Check and Change Current Active Slot on Android [Fastboot

Trying to flash a brand new Pixel 3 , but something looks wrong Some error messages and apparently stuck in fastboot

I built AOSP Android 11 Sunfish by my self and try to flash out images using fastboot into the phone The entire build and flashing process is

fastboot getvar currentslot  Read-only The current status of the FRU object in the slot fruObjectNum 5 - Error status 6

fastboot get active slot At this point, if I run the `fastboot flashall` command it errors out with a message saying `failed to identify current slot` `fastboot