anchor.diff:  
   The practices that we follow are:
   
  - * Always ping to a particular version of the plugin, e.g. `docker-compose#287293c4`. You can refer to any git ref. The agent will check this out the first time it encounters it and then re-use that checked out code.
  + * Always pin to a particular version of the plugin, e.g. `docker-compose#287293c4`. You can refer to any git ref. The agent will check this out the first time it encounters it and then re-use that checked out code.
   
    * Follow the [Unofficial Bash Strict Mode] and check your work with [shellcheck].
   
  
positive.code: 
  ## We love feedback!
  
  Agent plugins are still a new thing and we are evolving them as we learn more. We'd love feedback on how you use them and how we might make them better.
  
  [pipelines]: https://buildkite.com/docs/pipelines/defining-steps
  [hooks]: https://buildkite.com/docs/agent/hooks
  
negative.code:         run: app
  ```
  
  In the 2.x agent, this approach was only possible by either using the 
  docker environment variables, or writing a custom script. 
  
  ## Plugin sources
  
  