If multiple third-party modules shall be used for `oh-my-zsh` it has to
be possible to create another env which composes all the packages.
Now it can be done like this:
```
{ pkgs, ... }:
{
programs.zsh.enable = true;
programs.zsh.ohMyZsh = {
enable = true;
customPkgs = with pkgs; [
lambda-mod-zsh-theme
nix-zsh-completions
];
theme = "lambda-mod";
plugins = [ "nix" ];
};
}
```
Please keep in mind that this is not compatible with
`programs.zsh.ohMyZsh.custom`, only one of these options can be used
ATM.
Each package should store its outputs into
`$out/share/zsh/<output-name>`. Completions (and ZSH-only) extensions
should live in the `fpath` (`$out/share/zsh/site-functions`), plugins in
`.../plugins` and themes in `.../themes` (please refer to
fdb6bf6ed68c2f089ae6c729dfeaa3eddea2ce6a and 406d64aad162b3a4881747be4e24705fb5182573).
All scripts in `customPkgs` will be linked together using `linkFarm` to
provide a single directory for all scripts from all derivations in
`customPkgs` as suggested in https://github.com/NixOS/nixpkgs/pull/43282#issuecomment-410396365.