I have installed foreman 1.13, configured Puppet smart proxy and VMware
compute resource (with virtual distributed switch). I am able to create
host using UI successfully and all functionality is working fine.

But, when I try creating the same via "hammer", I am encountering below
error. I checked attributes that gets posted to API if I create through UI
and they are same as below.

Tried checking internet for any clues unsuccessfully. Can any one help me
with this?

2016-10-19 08:03:23 ce23a79b [app] [I] Parameters:
{"host"=>{"name"=>"testhammer.brocade.com", "compute_resource_id"=>1,
"hostgroup_id"=>2, "build"=>true, "enabled"=>true,
"provision_method"=>"image", "managed"=>true,
"compute_attributes"=>{"cpus"=>"2", "memory_mb"=>"2048",
"cluster"=>"Cluster-1", "guest_id"=>"rhel6_64Guest", "start"=>"1",
"name"=>"HardDisk", "size_gb"=>"40"}}}, "overwrite"=>true,
"interfaces_attributes"=>[{"type"=>"Nic::Managed", "managed"=>"true",
"primary"=>"true", "provision"=>"true", "virtual"=>"false",
"type"=>"VirtualVmxnet3"}}]}, "apiv"=>"v2"}
2016-10-19 08:03:23 ce23a79b [app] [I] Authorized user admin(Admin User)
2016-10-19 08:03:24 ce23a79b [app] [W] Failed to create a compute RedHat6.7
(VMware) instance brm-up-dbatest-5.brocade.com: undefined method `include?'
for nil:NilClass