fastboot • help -

getvar: fix broken 'fastboot flash' when partition has slots fastboot getvar currentslot Note: Linux, Mac, and Windows PowerShell users may have to type fastboot getvar current-slot here This will reveal the current boot slot your fastboot change slot error: Failed to identify current slot Diffing the results of fastboot getvar all with SD card, compared to eMMC, I see the following

fastboot set active slot fastboot getvar current-slot to get the current one , fastboot --set-active=not the current slot>, and then fastboot