title: Why is my Terraform output not working in module?
body: <p>I have the following simple setup:</p>
  
  <pre><code>~$ tree
  .
  ├── main.tf
  └── modules
      └── world
          └── main.tf
  ~$ cat main.tf
  output "root_module_says" {
      value = "hello from root module"
  }
  module "world" {
      source = "modules/world"
  }
  ~$ cat modules/world/main.tf
  output "world_module_says" {
      value = "hello from world module"
  }
  </code></pre>
  
  <p>I then run:</p>
  
  <pre><code>~$ terraform get
  ~$ terraform apply
  </code></pre>
  
  <p>I expect to see world_module_says in the outputs, but I do not, I only see root_module_says.
  This is really confusing as to why?</p>
  
  <p>If it helps:</p>
  
  <pre><code>~$ terraform --version
  v0.10.8
  </code></pre>