yubikey-full-disk-encryption: Invalid numeric value

I am trying to format LUKS partition by ykfde-format but getting an “Invalid numeric value” error from cryptsetup. I have enabled debug mode and can see the message:

Passing ‘8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c922d1c210a170356c9bab9ab18ecf0e2ae98e48316’ to ‘cryptsetup’

(don`t worry about the key, this is a dummy run)

I replaced the line: printf ‘%s\n’ “$YKFDE_PASSPHRASE” | cryptsetup luksFormat “$@”

To: printf ‘%s\n’ “$YKFDE_PASSPHRASE” | printf ‘%s\n’ “$@”

The line above does not pass the key to cryptsetup, but only parameters come from ykfde-format:

root@archiso / # ykfde-format --cipher aes-xts-plain64 --key-size 512 --hash sha256 --iter-time 5000 --type luks2 /dev/nvme0n1p4

YubiKey slot status ‘ykinfo -q -2’: 1 WARNING: This script will run ‘cryptsetup luksFormat --cipher aes-xts-plain64 --key-size 512 --hash sha256 --iter-time 5000 --type luks2 /dev/nvme0n1p4’. If this is not what you intended, please abort. Please provide the challenge. Enter challenge: 123456

Please repeat the challenge. Enter challenge: 123456 Running: ‘ykchalresp -2 8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92’… Remember to touch the device if necessary. Received response: ‘2d1c210a170356c9bab9ab18ecf0e2ae98e48316’ Passing ‘8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c922d1c210a170356c9bab9ab18ecf0e2ae98e48316’ to ‘cryptsetup’ –cipher aes-xts-plain64 –key-size 512 –hash sha256 –iter-time 5000 –type luks2 /dev/nvme0n1p4 New LUKS device successfully formatted

Please advise (: