Some modules are actually action plugins. These are tasks that will execute some code locally before transporting code to the remote host. Some example action plugins include copy, fetch, script, and template. The source to these plugins can be found in plugins/action/. Each plugin will have its own file in this directory that can be edited to have breakpoints inserted in order to debug the code that's executed, prior to (or in lieu of) sending code to the remote host. Debugging these is typically done with pdb, since most of the code is executed locally.