Using package.el to install and update but use-package for loading and configuring

Question

After recently learning about use-package I decided to port my configuration to it but found myself reluctant to give up the convenience of using package.el to install packages and keep them updated. I've found it a little tricky to combine use-package and package.el.

I'm generally interested in learning how people combine use-package with the package.el system, but for a more specific question, keep reading.

Here's what I want:

1. To have packages installed by the package manager so I can easily browse for packages and keep them updated through list-packages.
2. To configure and load packages exclusively through use-package, so I can easily see in my init file exactly what I'm loading and how it is configured.
3. Optionally, I'd like to also be able to install packages through use-package's :ensure keyword.

If I'm understanding correctly I want very little of what package-initialize does, basically only the way it sets up the load-path. Currently I have this in my configuration:

;(package-initialize)
(setq package-enable-at-startup nil)
(let ((default-directory "~/.emacs.d/elpa"))
  (normal-top-level-add-subdirs-to-load-path))
(require 'use-package)

The first, commented, line is so Emacs 25 doesn't helpfully add a (package-initialize) to my init file. The bit with normal-top-level-add-subdirs-to-load-path is an approximation to what package-initialize would make the load-path, an approximation that seems good enough.

This seems to achieve my desires 1 and 2, but not 3. If I try to use :ensure, I get an error message saying that package.el is not initialized. Calling package-initialize would fix that, but I wish to avoid that since a) I don't want all the myriad autoloads to be loaded (I prefer to use use-package to create precisely the autoloads I need), and b) I want to be able to easily avoid loading certain installed packages whenever I want (which is easy to do with use-package).

Does anyone have a recommendation for how to do this?

Answer 1

IIUC what you want to do is:

(package-initialize t)

Note the t argument, which is the key to your happiness here since it will (or should, at least) initialize package.el without activating all the installed packages.

Answer 2

With your current configuration, you've effectively disabled package.el, as you don't initialise the package manager and prevent Emacs from automatically initialising it. All you do in return is to add ELPA to the load-path, but that's just a small subset of what package.el does. I'm not sure why you do that, but it's not a setup that I'd recommend.

Specifically, you'll not get package autoloads with your approach, which means that initially no commands from any package will be available.

In other words, M-x will only offer you built-in commands. To add in commands from your packages you'd have to add explicit :commands definitions to all your use-package declarations, which amounts to a lot of maintenance effort—particularly for large packages such as Magit—for essentially zero gain—package.el gives you autoloads for free.

---

Combining use-package with package.el is actually very simple—y entire setup is based on this combination—but it's much better to let package.el actually to its job. Just initialise package.el at the very beginning of your init file:

(require 'package)
(setq package-enable-at-startup nil)   ; To prevent initialising twice
(add-to-list 'package-archives '("melpa" . "https://stable.melpa.org/packages/"))

(package-initialize)

For convenience you may subsequently want to bootstrap use-package, if it's not already installed:

(unless (package-installed-p 'use-package)
  (package-refresh-contents)
  (package-install 'use-package))

This let's you start an Emacs session on a fresh system, and your init.el will automatically install use-package.

Ultimately you need to load use-package:

(eval-when-compile
  (require 'use-package))

Now you can use use-package to install and configure packages:

(use-package magit                      ; The one and only Git frontend
  :ensure t
  :bind (("C-c v c" . magit-clone)
         ("C-c v v" . magit-status)
         ("C-c v g" . magit-blame)
         ("C-c v l" . magit-log-buffer-file)
         ("C-c v p" . magit-pull))
   :config (setq magit-save-repository-buffers 'dontask))

When Emacs now evaluates this form during startup, use-package will check whether Magit is already installed, and automatically install it if necessary.