emacs: Don't load all downloaded packages

1 files changed, 47 insertions, 3 deletions

diff --git a/.config/emacs/init.el b/.config/emacs/init.el
index 3932d6a..16555ce 100644
--- a/.config/emacs/init.el
+++ b/.config/emacs/init.el
@@ -82,16 +82,60 @@
         '(("gnu"          . 99)
           ("melpa-stable" .  5)
           ("melpa"        .  0)))
-  (package-initialize))
+  ;; Finally, initialize the package manager.  Pass the `t` argument
+  ;; to cause it to not go ahead and load all downloaded packages; and
+  ;; wait for (use-package) to request them.
+  (package-initialize t))
 
 ;; use-package.el
 (unless (package-installed-p 'use-package)
   (package-refresh-contents)
   (package-install 'use-package))
+(package-activate 'use-package)
 (eval-when-compile
-  (add-to-list 'load-path (concat user-emacs-directory "use-package"))
   (require 'use-package)
-  (setq use-package-always-ensure t))
+  ;; Have (use-package) calls eagerly install things.
+  (setq use-package-always-ensure t)
+  ;; Patch (use-package-ensure-elpa) to call (package-activate
+  ;; package) if the package is already installed, which is needed to
+  ;; make it work with the the `t` argument in
+  ;; `(package-initialize t)`.
+  ;;
+  ;; Apparently back in 2015 hacking (use-package-ensure-lazyelpa)
+  ;; wasn't necessary (https://emacs.stackexchange.com/a/16852), and
+  ;; I'm not sure what changed.
+  (defun use-package-ensure-lazyelpa (name args _state &optional _no-refresh)
+    (dolist (ensure args)
+      (let ((package
+             (or (and (eq ensure t) (use-package-as-symbol name))
+                 ensure)))
+        (when package
+          (require 'package)
+          (when (consp package)
+            (use-package-pin-package (car package) (cdr package))
+            (setq package (car package)))
+          (if (package-installed-p package)
+              (package-activate package)
+            (condition-case-unless-debug err
+                (progn
+                  (when (assoc package (bound-and-true-p
+                                        package-pinned-packages))
+                    (package-read-all-archive-contents))
+                  (if (assoc package package-archive-contents)
+                      (package-install package)
+                    (package-refresh-contents)
+                    (when (assoc package (bound-and-true-p
+                                          package-pinned-packages))
+                      (package-read-all-archive-contents))
+                    (package-install package))
+                  t)
+              (error
+               (display-warning 'use-package
+                                (format "Failed to install %s: %s"
+                                        name (error-message-string err))
+                                :error))))))))
+  (setq use-package-ensure-function 'use-package-ensure-lazyelpa))
+;; Load bind-key so that (use-package :bind) works.
 (require 'bind-key)
 
 ;; Themes ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;