Building yocto/poky image with wic?

Question

If I try to bitbake an image

bitbake name-of-image

with local.conf containing this:

…
WKS_FILE="directdisk-multi-rootfs.wks"
IMAGE_FSTYPES = "wic wic.bmap"
…

Then the build exits with error:

ERROR: Couldn't find correct bootimg_dir, exiting

If I try to run the wic command in cooked mode, the same error occours. And if I attempt to run wic in raw mode:

wic create directdisk-multi-rootfs -e name-of-image --rootfs-dir rootfs1=/home/user/yocto/dev-jetson-nano/build/tmp/work/jetson_nano-poky-linux/name-of-image/1.0-r0/rootfs/ --rootfs-dir rootfs2=/home/user/yocto/dev-jetson-nano/build/tmp/work/jetson_nano-poky-linux/name-of-image/1.0-r0/rootfs/ -b /home/user/yocto/dev-jetson-nano/build/tmp/work/jetson_nano-poky-linux/name-of-image/1.0-r0/recipe-sysroot/usr/share -k /home/user/yocto/dev-jetson-nano/build/tmp/deploy/images/jetson-nano -n /home/user/yocto/dev-jetson-nano/build/tmp/work/aarch64-poky-linux/wic-tools/1.0-r0/recipe-sysroot-native

I still get the same error.

I need to create an image for the jetson-nano that can use RAUC update tool which needs two rootfs to work. Wic tool seems to be able to do that. How to upload it and if it will even work on the jetson nano is another question, but right now I just want to be able to make an image with wic.

EDIT: As this is for a SD-card I made my own version of the "directdisk-multi-rootfs.wks" file with this:

part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 1024 --sourceparams="loader=u-boot"
part / --source rootfs --rootfs-dir=rootfs1 --ondisk mmcblk --fstype=ext4 --label platform --align 1024
part /rescue --source rootfs --rootfs-dir=rootfs2 --ondisk mmcblk --fstype=ext4 --label secondary --align 1024

bootloader  --timeout=0  --append="rootwait rootfstype=ext4 video=vesafb vga=0x318 console=tty0 console=ttyS0,115200n8"

This gives me a new but very similar error:

ERROR: No boot files defined, IMAGE_BOOT_FILES unset for entry #1