[Google Pixel 6 Pro] mad-murdock:
Update: Problem fixed as @Lughnasadh said: flash.android.com fixes the issue a buggy fastboot version can create.

=======

First the log:

┬─[sven@BeineAufsSofa:~/D/raven-tq2a.230305.008.e1]─[13:36:16]─[I]
╰─>$ sudo ./flash-all.sh
Sending 'bootloader_b' (12094 KB) OKAY [ 0.405s]
Writing 'bootloader_b' (bootloader) Flashing pack version slider-1.2-9465321
(bootloader) flashing platform gs101
(bootloader) Validating partition ufs
(bootloader) Validating partition ufs
(bootloader) Validating partition partition:0
(bootloader) Validating partition partition:1
(bootloader) Validating partition partition:2
(bootloader) Validating partition partition:3
(bootloader) Validating partition bl1_b
(bootloader) Validating partition pbl_b
(bootloader) Validating partition bl2_b
(bootloader) Validating partition abl_b
(bootloader) Validating partition bl31_b
(bootloader) Validating partition tzsw_b
(bootloader) Validating partition gsa_b
(bootloader) Validating partition ldfw_b
(bootloader) Flashing partition ufs
(bootloader) Flashing partition ufs
(bootloader) Flashing partition partition:0
(bootloader) Flashing partition partition:1
(bootloader) Flashing partition partition:2
(bootloader) Flashing partition partition:3
(bootloader) Flashing partition bl1_b
(bootloader) Flashing partition pbl_b
(bootloader) Flashing partition bl2_b
(bootloader) Flashing partition abl_b
(bootloader) Flashing partition bl31_b
(bootloader) Flashing partition tzsw_b
(bootloader) Flashing partition gsa_b
(bootloader) Flashing partition ldfw_b
(bootloader) Loading sideload ufsfwupdate
OKAY [ 3.015s]
Finished. Total time: 3.422s
Rebooting into bootloader OKAY [ 0.000s]
Finished. Total time: 0.053s
< waiting for any device >
Sending 'radio_b' (94452 KB) OKAY [ 3.189s]
Writing 'radio_b' (bootloader) Flashing pack version g5123b-112825-230302-M-9675756
(bootloader) Flashing partition modem_b
OKAY [ 0.121s]
Finished. Total time: 3.316s
Rebooting into bootloader OKAY [ 0.000s]
Finished. Total time: 0.050s
< waiting for any device >
--------------------------------------------
Bootloader Version...: slider-1.2-9465321
Baseband Version.....: g5123b-112825-230302-B-9675756
Serial Number........: 23041FDEE005AM
--------------------------------------------
extracting android-info.txt (0 MB) to RAM...
Checking 'product' OKAY [ 0.000s]
Checking 'version-bootloader' OKAY [ 0.000s]
Checking 'version-baseband' OKAY [ 0.000s]
Setting current slot to 'b' OKAY [ 0.085s]
extracting boot.img (64 MB) to disk... took 0.524s
archive does not contain 'boot.sig'
Sending 'boot_b' (65536 KB) OKAY [ 2.094s]
Writing 'boot_b' OKAY [ 0.076s]
archive does not contain 'init_boot.img'
extracting dtbo.img (16 MB) to disk... took 0.054s
archive does not contain 'dtbo.sig'
Sending 'dtbo_b' (16384 KB) OKAY [ 0.521s]
Writing 'dtbo_b' OKAY [ 0.022s]
archive does not contain 'dt.img'
extracting pvmfw.img (1 MB) to disk... took 0.007s
archive does not contain 'pvmfw.sig'
Sending 'pvmfw_b' (1024 KB) OKAY [ 0.034s]
Writing 'pvmfw_b' OKAY [ 0.003s]
archive does not contain 'recovery.img'
extracting vbmeta.img (0 MB) to disk... took 0.000s
archive does not contain 'vbmeta.sig'
Sending 'vbmeta_b' (12 KB) OKAY [ 0.001s]
Writing 'vbmeta_b' OKAY [ 0.002s]
extracting vbmeta_system.img (0 MB) to disk... took 0.000s
archive does not contain 'vbmeta_system.sig'
Sending 'vbmeta_system_b' (4 KB) OKAY [ 0.001s]
Writing 'vbmeta_system_b' OKAY [ 0.002s]
extracting vbmeta_vendor.img (0 MB) to disk... took 0.000s
archive does not contain 'vbmeta_vendor.sig'
Sending 'vbmeta_vendor_b' (4 KB) OKAY [ 0.001s]
Writing 'vbmeta_vendor_b' OKAY [ 0.002s]
extracting vendor_boot.img (64 MB) to disk... took 0.473s
archive does not contain 'vendor_boot.sig'
Sending 'vendor_boot_b' (65536 KB) OKAY [ 2.145s]
Writing 'vendor_boot_b' OKAY [ 0.077s]
archive does not contain 'vendor_kernel_boot.img'
extracting super_empty.img (0 MB) to disk... took 0.000s
extracting product.img (2620 MB) to disk... took 21.866s
[liblp] Partition product_b will resize from 0 bytes to 2747355136 bytes
extracting system.img (827 MB) to disk... took 7.403s
[liblp] Partition system_b will resize from 0 bytes to 867323904 bytes
extracting system_ext.img (358 MB) to disk... took 3.044s
[liblp] Partition system_ext_b will resize from 0 bytes to 376356864 bytes
extracting system_other.img (25 MB) to disk... took 0.215s
[liblp] Partition system_a will resize from 0 bytes to 27095040 bytes
extracting vendor.img (517 MB) to disk...fastboot: error:
failed to extract 'vendor.img': I/O error

I seem to not have a vendor partition. when i tried flashing manually, i got the following output:

┬─[sven@BeineAufsSofa:~/D/raven-tq1a.230105.002]─[13:33:06]─[I]
╰─>$ sudo fastboot flash vendor_b vendor.img
Resizing 'vendor_b' FAILED (remote: 'Invalid command resize-logical-partition:vendor_b:534085632')
fastboot: error: Command failed
┬─[sven@BeineAufsSofa:~/D/raven-tq1a.230105.002]─[13:34:08]─[I]
╰─>$ sudo fastboot flash --slot=b vendor vendor.img
Warning: vendor does not support slots, and slot b was requested.
Sending sparse 'vendor' 1/3 (254972 KB) OKAY [ 8.301s]
Writing 'vendor' FAILED (remote: 'partition (vendor) not found')
fastboot: error: Command failed

Background:

I had magisk and a custom kernel installed and so i didnt get any updates anymore after the december update. I removed magisk and flashed the old kernel, but still i didnt get any official update. so in the and, i downloaded latest factory image. i unzipped, removed the "delete userdata"/"-w" part from flash-all.sh and then executed that script.

from the first time i got that i/o error regarding vendor.img - i tried the january and february factory images, too. with no changed to that error....

i dont dare to boot without a vendor partition, so please tell me what i could do. I am prepared to lose my userdata partition in worst case, but i hope this wont happen