Dynamic inputs and bundlesequence without common bundles

gistfile1.txt

newatson@ltipc682:~/.cfagent/inputs$ cat promises.cf
body common control
{

    bundlesequence => { "first", @{first.bs} };

    inputs => { "first.cf", @{first.inputs} };
}

newatson@ltipc682:~/.cfagent/inputs$ cat first.cf 
bundle agent first
{
    vars:
        "bs" slist => { "main", "post" };
        "inputs" slist => { "b.cf" };
}
newatson@ltipc682:~/.cfagent/inputs$ cat b.cf 
bundle agent main
{
    reports:
        cfengine::
            "main bundle";
}

bundle agent post
{
    reports:
        cfengine::
            "post bundle";
}

newatson@ltipc682:~/.cfagent/inputs$ cf-agent -f ./promises.cf
R: main bundle
R: post bundle

newatson@ltipc682:~/.cfagent/inputs$ cf-promises -V

   @@@      
   @@@      cf-promises
            
 @ @@@ @    CFEngine Core 3.4.1
 @ @@@ @    
 @ @@@ @    
 @     @    
   @@@      
   @ @      
   @ @      
   @ @      

Copyright (C) CFEngine AS 2008-2012
See Licensing at http://cfengine.com/3rdpartylicenses

Interestingly, the agent seems to evaluate first secretly here:
cf3>  Loaded persistent memory
cf3> ***********************************************************
cf3>  -> Found a policy server (hub) on 172.26.2.4
cf3>  -> Input file is outside default repository, validating it
cf3>  -> Promises seem to change
cf3>  -> Input file is changed since last validation, validating it
cf3>  -> Verifying the syntax of the inputs...
cf3> Checking policy with command ""/home/newatson/.cfagent/bin/cf-promises" -f "./promises.cf""
cf3>   > Parsing file ./promises.cf
cf3> Initiate variable convergence...
cf3>   > Parsing file ./first.cf
cf3> Initiate variable convergence...
cf3>   > Parsing file ./b.cf
cf3> Initiate variable convergence...
cf3> Initiate variable convergence...

Later the bundlesequence is determined and used:
cf3> Initiate variable convergence...
cf3>  -> Additional class defined: am_policy_hub
cf3>  -> Immunizing against parental death
cf3> -> Bundlesequence =>  {'first','main','post'}
cf3> 
cf3> *****************************************************************
cf3> BUNDLE first