does not create a boot.img

[kivi]

When I run this command

rootkernel.cmd kernel.elf boot.img

I get following output

Rootkernel V5.23

- Unpacking kernel
 Found elf boot image
 Kernel version: 3.10.84-perf-gcb77bab-03149-gfe8d4a8
 Found appended DTB
- Detected vendor: somc (Sony), device: kugo, variant: row
- Unpacking initramfs
- Detected platform: 64-bit
- Detected Android version: 7.1.1
- dm-verity is enabled. Disable? (Say yes if you modify /system) [Y/n] Y
 Disabling dm-verity
- Sony RIC is enabled. Disable? [Y/n] Y
 Disabling Sony RIC
- There is no TWRP template for kugo. Install anyway? [y/N] Y
 Installing TWRP
 Compressing TWRP image
- DRM fix is unsuppported/untested for model kugo. Install anyway? [y/N] Y
- Install busybox? [Y/n] Y
- Creating new initramfs
- Creating boot image
- Cleaning up
Done

A boot.img is not created