Error write_gcm: can not take infinite value for swap/percent/value on machines without swap

[gdsotirov]

• Version of collectd: 6.1.3-1
• Operating system / distribution: CentOS Linux release 8.3.2011

Expected behavior

No errors with default configuration on virtual machine instances without swap.

Actual behavior

Constantly repeating errors in the journal (e.g. systemctl status stackdriver-agent or journalctl -xe) with the first line in red:

write_gcm: can not take infinite value
collectd[1520]: write_gcm: wg_typed_value_create_from_value_t_inline failed for swap/percent/value! Continuing.

Steps to reproduce

1. Install Cloud Monitoring agent following these instructions.
2. Check agent status (e.g. systemctl status stackdriver-agent) or for errors in general (e.g. journalctl -xe).

The workaround is of course to disable the swap plugin, but having virtual machine instances without swap is common nowadays, so there should not be error at all.