D8 Notes: 'Fields pending deletion' Exception

While working on a module that defines a custom field I attempted a reinstall of the module. During the uninstall process I received the following exception:

exception 'Drupal\Core\Extension\ModuleUninstallValidatorException' with  [error]
message 'The following reasons prevent the modules from being uninstalled:
Fields pending deletion' 

Luckily this one has a very simple fix. Head on over to your Status page (under admin >> reports) and click to run cron manually. Once cron runs, it cleans up all the little tidbits still stored in the system and then you can easily carry on with your development fun.