It looks like the show hardware dmi operational mode command is broken in 1.4.0-RC2 (and presumably 1.4.0-RC1):
trae@cr01b-vyos:~$ show hardware dmi -vbash: /opt/vyatta/bin/vyatta-show-dmi: No such file or directory
Here's how it used to look:
trae@cr01a-vyos:~$ show hardware dmi bios_date: 10/30/2020 bios_vendor: American Megatrends Inc. bios_version: 3.4 board_asset_tag: IBM SoftLayer board_name: X11DPU board_vendor: Supermicro board_version: 1.10 chassis_asset_tag: IBM SoftLayer chassis_type: 1 chassis_vendor: Supermicro chassis_version: 0123456789 product_family: To be filled by O.E.M. product_name: SYS-6019U-TN4R4T product_sku: To be filled by O.E.M. product_version: 0123456789 sys_vendor: Supermicro