Symptom:
When we use vault kv get to fetch CA from pki endpoint, we hit error
$ vault kv get pki/ca/pem
Error reading pki/ca/pem: invalid character '-' in numeric literal
Workaround:
The proper way to fetch it is:
$ vault kv get -field=certificate pki/ca/pem
or
$ vault read -field=certificate pki/ca/pem