nixos-options	helm-nixos-options	company-nixos-options

The function helm-nixos-options is the one that you want to bind. You are free to choose where and if you want it global you can have this.

(global-set-key (kbd "C-c C-S-n") 'helm-nixos-options)

It looks like this

The description of the option is shown in the minibuffer

If you want more information, there is a detailed buffer when you press return

There are also other actions like inserting the current match into the buffer

Add company-nixos-options to allowed company-mode backends list

(add-to-list 'company-backends 'company-nixos-options)

For now it shows the documentation of the option in a popup-buffer.

Contains utility functions to work with nix-shell sandboxes.

• nix-shell-command to compose a nix-shell command string that can be passed to the command-line
• nix-shell that directly executes a command in the given sandbox
• nix-find-sandbox searches from the given path upwards until it finds a *.nix file.
• nix-current-sandbox searches from the current working directroy upwards until it finds a *.nix file
• nix-executable-find, a replacement for the built-in executable-find. It searches in the given sandbox for executable.

With these utility functions, flycheck can easily be used with Nix:

(setq flycheck-command-wrapper-function
        (lambda (command) (apply 'nix-shell-command (nix-current-sandbox) command))
      flycheck-executable-find
        (lambda (cmd) (nix-executable-find (nix-current-sandbox) cmd)))

To use haskell-mode together with Nix, add these lines to your configuration:

(setq haskell-process-wrapper-function
        (lambda (args) (apply 'nix-shell-command (nix-current-sandbox) args)))