flash-all.sh FAILED transcript ("remote: partition [bootb] doesn't exist")

gistfile1.txt

$ sudo fastboot devices
FA6A20303377    fastboot

$ sudo ./flash-all.sh
target reported max download size of 536870912 bytes
sending 'bootloaderb' (32728 KB)...
OKAY [  0.836s]
writing 'bootloaderb'...
(bootloader) Valid bootloader version.
OKAY [  1.600s]
finished. total time: 2.435s
rebooting into bootloader...
OKAY [  8.593s]
finished. total time: 8.693s
< waiting for any device >
target reported max download size of 536870912 bytes
sending 'radiob' (57192 KB)...
OKAY [  1.428s]
writing 'radiob'...
OKAY [  0.909s]
finished. total time: 2.337s
rebooting into bootloader...
OKAY [  0.006s]
finished. total time: 0.106s
target reported max download size of 536870912 bytes
archive does not contain 'boot.sig'
archive does not contain 'recovery.img'
archive does not contain 'system.sig'
archive does not contain 'vendor.sig'
wiping userdata...
Creating filesystem with parameters:
    Size: 122633060352
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 8192
    Inode size: 256
    Journal blocks: 32768
    Label:
    Blocks: 29939712
    Block groups: 914
    Reserved block group size: 1024
Created filesystem with 11/7487488 inodes and 518062/29939712 blocks
--------------------------------------------
Bootloader Version...: 8996-012001-1610061102
Baseband Version.....: 8996-012511-1611190200
Serial Number........: FA6A20303377
--------------------------------------------
checking product...
OKAY [  0.050s]
checking version-bootloader...
OKAY [  0.051s]
checking version-baseband...
OKAY [  0.050s]
sending 'bootb' (24821 KB)...
OKAY [  0.642s]
writing 'bootb'...
(bootloader) Flashing active slot "_b"
FAILED (remote: partition [bootb] doesn't exist)
finished. total time: 1.095s