Comment 3 for bug 1938263

I was trying to follow https://netplan.io/examples/ but it looks like the "default" key word cannot be used.

Linux srv2 5.4.0-81-generic #91-Ubuntu SMP Thu Jul 15 19:09:17 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

(generate:3732): GLib-WARNING **: 19:34:50.050: GError set over the top of a previous GError or uninitialized memory.
This indicates a bug in someone's code. You must ensure an error is NULL before it's set.
The overwriting error message was: /etc/netplan/00-installer-config.yaml:18:11: Error in network definition: unicast route must include both a 'to' and 'via' IP
          - to: default
          ^
/etc/netplan/00-installer-config.yaml:18:17: Error in network definition: invalid IP family '-1'
          - to: default
                ^