[Google Pixel 2 Questions & Answers] iamnotreallyhere:
It still sounds like you are not using the latest tools. Are you installing the platform tools or are you using the extracted zip?

the script is going to use whatever is installed on your system.

The first thing I did was download: https://dl.google.com/android/repository/platform-tools-latest-windows.zip

I used this image Android 8.1 stock: https://dl.google.com/dl/android/aosp/taimen-opm1.171019.011-factory-2df1c1cb.zip

I extracted platform tools to my desktop. I opened the file location and did a Shift > Right click - within the folder containing the tools and opened CMD or Powershell( or you can just CD to the directory).

I copied all the commands from the script and ran them one at a time making sure I was using the tools from the zip file and not my system.

and just went down the line.

Like this:

PS C:\Users\myusername\Desktop\platform-tools> C:\Users\myusername\Desktop\platform-tools\fastboot.exe --set-active=b

Setting current slot to 'b'...

OKAY [ 0.016s]

finished. total time: 0.017s

PS C:\Users\myusername\Desktop\platform-tools> cd C:\Users\myusername\Downloads\nv3

PS C:\Users\myusername\Downloads\nv3> C:\Users\myusername\Desktop\platform-tools\fastboot.exe flash bootloader bootloader-walleye-mw8998-002.0066.00.img

target reported max download size of 536870912 bytes

sending 'bootloader_b' (38644 KB)...

OKAY [ 0.829s]

writing 'bootloader_b'...

(bootloader) Updating: partition:0 @00002000 sz=0000B000

(bootloader) Updating: partition:1 @0000D000 sz=0000B000

(bootloader) Updating: partition:2 @00018000 sz=0000B000

(bootloader) Updating: partition:3 @00023000 sz=0000B000

(bootloader) Updating: partition:4 @0002E000 sz=0000B000

(bootloader) Updating: partition:5 @00039000 sz=0000B000

(bootloader) Updating: cmnlib64 @00044000 sz=00048000

(bootloader) Updating: cmnlib @0008C000 sz=00037000

(bootloader) Updating: devcfg @000C3000 sz=0000F000

(bootloader) Updating: hyp @000D2000 sz=00040000

(bootloader) Updating: keymaster [MENTION=4422149]0011[/MENTION]2000 sz=00046000

(bootloader) Updating: lockbooter [MENTION=290768]001[/MENTION]58000 sz=00016000

(bootloader) Updating: pmic [MENTION=290768]001[/MENTION]6E000 sz=0000D000

(bootloader) Updating: rpm [MENTION=4848019]0017[/MENTION]B000 sz=0003A000

(bootloader) Updating: tz [MENTION=290768]001[/MENTION]B5000 sz=001DB000

(bootloader) Updating: xbl [MENTION=2077256]003[/MENTION]90000 sz=003A2000

(bootloader) Updating: apdp [MENTION=262411]0073[/MENTION]2000 sz=00004000

(bootloader) Updating: msadp [MENTION=262411]0073[/MENTION]6000 sz=00004000

(bootloader) Updating: hosd [MENTION=262411]0073[/MENTION]A000 sz=01E1E000

(bootloader) Updating: abl @02558000 sz=00065000

OKAY [ 0.894s]

finished. total time: 1.724s

PS C:\Users\myusername\Downloads\nv3> C:\Users\myusername\Desktop\platform-tools\fastboot.exe reboot-bootloader

rebooting into bootloader...

OKAY [ 0.002s]

finished. total time: 0.002s

PS C:\Users\myusername\Downloads\nv3> C:\Users\myusername\Desktop\platform-tools\fastboot.exe flash radio radio-walleye-g8998-00164-1710262031.img

target reported max download size of 536870912 bytes

sending 'radio_b' (60428 KB)...

OKAY [ 1.293s]

writing 'radio_b'...

(bootloader) Updating: modem @00001000 sz=03B01000

OKAY [ 0.552s]

finished. total time: 1.848s

PS C:\Users\myusername\Downloads\nv3> C:\Users\myusername\Desktop\platform-tools\fastboot.exe reboot-bootloader

rebooting into bootloader...

OKAY [ 0.001s]

finished. total time: 0.002s

PS C:\Users\myusername\Downloads\nv3> C:\Users\myusername\Desktop\platform-tools\fastboot.exe -w update image-walleye-opm1.171019.011.zip

extracting android-info.txt (0 MB) to RAM...

extracting boot.img (32 MB) to disk... took 0.134s

target reported max download size of 536870912 bytes

archive does not contain 'boot.sig'

archive does not contain 'boot_other.img'

extracting dtbo.img (8 MB) to disk... took 0.020s

archive does not contain 'dtbo.sig'

archive does not contain 'dt.img'

archive does not contain 'recovery.img'

extracting system.img (1920 MB) to disk... took 8.309s

archive does not contain 'system.sig'

extracting system_other.img (568 MB) to disk... took 2.987s

archive does not contain 'system.sig'

extracting vbmeta.img (0 MB) to disk... took 0.000s

archive does not contain 'vbmeta.sig'

extracting vendor.img (347 MB) to disk... took 1.721s

archive does not contain 'vendor.sig'

archive does not contain 'vendor_other.img'

wiping userdata...

mke2fs 1.43.3 (04-Sep-2016)

Creating filesystem with 13933563 4k blocks and 3489792 inodes

Filesystem UUID: 1f46fc9a-edc7-11e7-aa2c-2daa660ba492

Superblock backups stored on blocks:

32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,

4096000, 7962624, 11239424

Allocating group tables: done

Writing inode tables: done

Creating journal (65536 blocks): done

Writing superblocks and filesystem accounting information: done

--------------------------------------------

Bootloader Version...: mw8998-002.0066.00

Baseband Version.....: g8998-00164-1710262031

Serial Number........: HT696969696969

--------------------------------------------

checking product...

OKAY [ 0.001s]

checking version-bootloader...

OKAY [ 0.002s]

checking version-baseband...

OKAY [ 0.001s]

sending 'boot_b' (32768 KB)...

OKAY [ 0.699s]

writing 'boot_b'...

OKAY [ 0.001s]

sending 'dtbo_b' (8192 KB)...

OKAY [ 0.477s]

writing 'dtbo_b'...

OKAY [ 0.001s]

erasing 'system_b'...

OKAY [ 0.316s]

sending sparse 'system_b' 1/4 (524284 KB)...

OKAY [ 11.667s]

writing 'system_b' 1/4...

OKAY [ 0.001s]

sending sparse 'system_b' 2/4 (524284 KB)...

OKAY [ 13.907s]

writing 'system_b' 2/4...

OKAY [ 0.001s]

sending sparse 'system_b' 3/4 (524284 KB)...

OKAY [ 13.876s]

writing 'system_b' 3/4...

OKAY [ 0.002s]

sending sparse 'system_b' 4/4 (393508 KB)...

OKAY [ 11.018s]

writing 'system_b' 4/4...

OKAY [ 0.001s]

erasing 'system_a'...

OKAY [ 2.084s]

sending sparse 'system_a' 1/2 (524284 KB)...

OKAY [ 11.561s]

writing 'system_a' 1/2...

OKAY [ 0.001s]

sending sparse 'system_a' 2/2 (57592 KB)...

OKAY [ 3.758s]

writing 'system_a' 2/2...

OKAY [ 0.001s]

sending 'vbmeta_b' (4 KB)...

OKAY [ 0.288s]

writing 'vbmeta_b'...

OKAY [ 0.001s]

erasing 'vendor_b'...

OKAY [ 0.116s]

sending 'vendor_b' (355428 KB)...

OKAY [ 7.594s]

writing 'vendor_b'...

OKAY [ 0.001s]

Setting current slot to 'b'...

OKAY [ 1.722s]

erasing 'userdata'...

OKAY [ 0.759s]

sending 'userdata' (4669 KB)...

OKAY [ 0.108s]

writing 'userdata'...

OKAY [ 0.001s]

rebooting...

finished. total time: 80.060s

fastboot flash bootloader bootloader-walleye-mw8998-002.0066.00.img

fastboot reboot-bootloader

fastboot flash radio radio-walleye-g8998-00164-1710262031.img

fastboot reboot-bootloader

fastboot -w update image-walleye-opm2.171019.012.zip