The recommended order for the module loading has been changed. The last
module to be loaded should be 'completion'. This ensures all completions
set by other modules are dumped and included in the completion.
Because of this, any compdefs like this one (making the pacman aliases
use pacman completion) must be set in the compdefs.zsh file, and loaded
with the completion module. This means the compdefs must be wrapped with
conditional statements to ensure such aliases/functions have been set by
previous modules. I may abstract this conditional to a function in the
future to make this an easier process.
