get_attribute not evaluating

[DeWayne Filppi]

I'm attempting evaluate 'get_attribute' in an operation input clause like
so:

    fortigate_vnf_baseline_config:
      type: aria.terminal.raw
      interfaces:
        Standard:
          create:
            inputs:
              terminal_auth: &terminal_auth
                user: admin
                password: ''
                ip: { get_attribute: [ fortigate_ip, floating_ip_address ] }

When I run the install workflow, the code that evaluates "ip" sees the
string literal "{ get_attribute: [ fortigate_ip, floating_ip_address ] }".

>From the spec it seems this should evaluate fine.   This seems pretty
basic, so it seems unlikely to be a bug.  Perhaps because it's in a YAML
macro?

-- DeWayne