Change:
</section> <ins> <section xml:id="sec-emacs"> <title>Emacs</title> <section xml:id="sec-emacs-config"> <title>Configuring Emacs</title> <para> The Emacs package comes with some extra helpers to make it easier to configure. <varname>emacsWithPackages</varname> allows you to manage packages from ELPA. This means that you will not have to install that packages from within Emacs. For instance, if you wanted to use <literal>company</literal>, <literal>counsel</literal>, <literal>flycheck</literal>, <literal>ivy</literal>, <literal>magit</literal>, <literal>projectile</literal>, and <literal>use-package</literal> you could use this as a <filename>~/.config/nixpkgs/config.nix</filename> override: </para> <screen> { packageOverrides = pkgs: with pkgs; { myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [ company counsel flycheck ivy magit projectile use-package ])); } } </screen> <para> You can install it like any other packages via <command>nix-env -iA myEmacs</command>. However, this will only install those packages. It will not <literal>configure</literal> them for us. To do this, we need to provide a configuration file. Luckily, it is possible to do this from within Nix! By modifying the above example, we can make Emacs load a custom config file. The key is to create a package that provide a <filename>default.el</filename> file in <filename>/share/emacs/site-start/</filename>. Emacs knows to load this file automatically when it starts. </para> <screen> { packageOverrides = pkgs: with pkgs; rec { myEmacsConfig = writeText "default.el" '' ;; initialize package (require 'package) (package-initialize 'noactivate) (eval-when-compile (require 'use-package)) ;; load some packages (use-package company :bind ("&lt;C-tab&gt;" . company-complete) :diminish company-mode :commands (company-mode global-company-mode) :defer 1 :config (global-company-mode)) (use-package counsel :commands (counsel-descbinds) :bind (([remap execute-extended-command] . counsel-M-x) ("C-x C-f" . counsel-find-file) ("C-c g" . counsel-git) ("C-c j" . counsel-git-grep) ("C-c k" . counsel-ag) ("C-x l" . counsel-locate) ("M-y" . counsel-yank-pop))) (use-package flycheck :defer 2 :config (global-flycheck-mode)) (use-package ivy :defer 1 :bind (("C-c C-r" . ivy-resume) ("C-x C-b" . ivy-switch-buffer) :map ivy-minibuffer-map ("C-j" . ivy-call)) :diminish ivy-mode :commands ivy-mode :config (ivy-mode 1)) (use-package magit :defer :if (executable-find "git") :bind (("C-x g" . magit-status) ("C-x G" . magit-dispatch-popup)) :init (setq magit-completing-read-function 'ivy-completing-read)) (use-package projectile :commands projectile-mode :bind-keymap ("C-c p" . projectile-command-map) :defer 5 :config (projectile-global-mode)) ''; myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [ (runCommand "default.el" {} '' mkdir -p $out/share/emacs/site-lisp cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el '') company counsel flycheck ivy magit projectile use-package ])); }; } </screen> <para> This provides a fairly full Emacs start file. It will load in addition to the user's presonal config. You can always disable it by passing <command>-q</command> to the Emacs command. </para> </section> </section> </ins> </chapter>

Discussion:
I spent a long time trying to figure out how to make an that contained my personal configuration. I wanted to avoid having an `. I don't know where else to put this sort of knowledge, and it may not be idiomatic emacs, but I think it is worth documenting:
Agree - I have a completely different way to do this, which I'm not sure is particularly nice. I chuck my into ... Could probably write a nice wrapper for this kind of thing to make it cleaner.
Similar issue:
looks like you solved this similarly to me (except properly). Lets chase up the pull request rejection, and see what we can do.