zsh: remove search for installed completions

[jpotier]

1. Takes a lot of time: seriously, this takes 2 seconds at first launch, and like .25 second for the following launches;
2. Is redundant with using oh-my-zsh, completions is set in there, works well, and does not lag as much (why?). For using the oh-my-zsh config, one must enable zsh first.

[rycee]

I'm agnostic w.r.t. this but perhaps @uvNikita has opinions?

[jpotier]

Yeah, I'm curious too

[uvNikita]

Hmm, the thought behind this code was that the completions should work for users who want to use vanilla zsh:

1. zsh is not enabled in the system
2. zsh is enabled via Home Manager and enableCompletion is set to true
3. oh-my-zsh is not enabled via Home Manager

This code was taken from NixPkgs programs.zsh module, which will be executed only if programs.zsh was enabled in the system configuration. However, I just tested the standard completions with the scenario described above and it works. In my case, fpath with such settings is set to:

/usr/local/share/zsh/site-functions /nix/store/<hash>-zsh-5.4.2/share/zsh/site-functions /nix/store/<hash>-zsh-5.4.2/share/zsh/5.4.2/functions

Which seems to be correct. Maybe zsh package was fixed at some point, but programs.zsh was not updated? In any case, I think we can delete this code from Home Manager, at least it works correctly on my setup.

Thank you for raising the issue!

[rycee]

Thanks @uvNikita (btw, check your Matrix chat)!

@jpotier Would you mind changing the first commit line to "zsh: remove search for installed completions" (module name + ":" + description in imperative mood). Also please wrap the body at 72 characters.

[jpotier]

Thanks @uvNikita for your comments. @rycee Commit title and body have been changed.

[uvNikita]

I rephrased the commit message a bit and rebased into master 721f924. Thanks again for PR!