A python-novaclient bug prevented the 'nova interface-list' command from displaying MAC addresses. Specifically, the interface-list command incorrectly expected MAC address information in the JSON response to be in a column named 'mac_address'. However, the column was actually named 'mac_addr'.
This prevented the 'nova interface-list' command from retrieving and, consequently, displaying MAC address information.
With this fix, python-novaclient now expects MAC addresses from the correct 'mac_addr' column. This allows the 'nova interface-list' command to retrieve and display MAC address information.