[...]
fastboot -w update image-nakasi-ktu84p.zip
target didn't report max-download-size
sending 'bootloader' (2100 KB)...
OKAY [ 0.262s]
writing 'bootloader'...
OKAY [ 0.601s]
finished. total time: 0.863s
rebooting into bootloader...
OKAY [ 0.015s]
finished. total time: 0.065s
extracting android-info.txt (0 MB)...
extracting boot.img (4 MB)...
target didn't report max-download-size
The archive doesn't sign correctly.
archive does not contain 'boot.sig'
archive does not contain 'dtbo.img'
The link below mentions a problem with dtbo.img.
archive does not contain 'dt.img'
extracting recovery.img (5 MB)...
archive does not contain 'recovery.sig'
extracting system.img (628 MB)...
archive does not contain 'system.sig'
archive does not contain 'vbmeta.img'
archive does not contain 'vendor.img'
wiping userdata...
Couldn't parse erase-block-size '0x'.
Couldn't parse logical-block-size '0x'.
mke2fs 1.44.6 (5-Mar-2019)
/tmp/TemporaryFile-fnXNLB:
Looks like the install script was out of date and wasn't linking things correctly.
.
Unimplemented ext2 library function while setting up superblock
/usr/lib/android-sdk/platform-tools/mke2fs failed with status 1
mke2fs failed: 1
error: Cannot generate image for userdata
At this point, if it's not bricked, it looks a bit more like software to me. A little research found similar problems.