The output of "show ipv6 bgp summary" is unexpected if there is no IPv6 BGP session configured

[kevinskwang]

Description

We saw some errors using CLI "show ipv6 bgp summary" as below: _$show ipv6 bgp sum Usage: show ipv6 bgp sum [OPTIONS] Try "show ipv6 bgp sum -h" for help.

Error: bgp summary from bgp container in invalid format_

It will only happen on the devices which don't configure the IPv6 BGP session. IPv4 should be the same thing.

Steps to reproduce the issue

1. Make sure there isn't IPv6 BGP session configured in config_db
2. Run CLI "config reload"
3. Run CLI "show ipv6 bgp summary" Then you should see above errors. Tried on branch 202205 and 202012.

Describe the results you received

Describe the results you expected

Additional information you deem important (e.g. issue happens only occasionally)

Output of show version

(paste your output here)