emacs -Q pkg debug helper macro

[Kaushal Modi]

Hi all,

Recently while debugging the behavior of an external package in an emacs -Q session, I came up with the below.

Would it be helpful to have this or something similar in the core?

(defmacro emacs-pkg-debug-setup (pkg-alist &rest body)

  "Install packages in PKG-ALIST and evaluate BODY.

Each element of PKG-ALIST has the form (((ID . LOCATION) . (PKG1 PKG2 ..)) ..).

The ID and LOCATION are the same as the ones in `package-archives'.

PKG1, PKG2, .. are package names from the ID archive.

Example usage:

1. Launch 'emacs -Q'.

2. Copy this macro definition to its scratch buffer and evaluate it.

3. Evaluate a minimum working example using this macro as below:

     (emacs-pkg-debug-setup '(((\"org\" . \"http://orgmode.org/elpa/\") . (org)))

       (org-mode)) "

  (declare (indent 1) (debug t))

  `(progn

     (require 'package)

     (setq user-emacs-directory (concat temporary-file-directory

                                        (getenv "USER") "/" ".emacs.d-debug/"))

     (setq package-user-dir (concat user-emacs-directory "elpa/"))

     (let ((pkgs ()))

       (dolist (archive-alist ,pkg-alist)

         (add-to-list 'package-archives (car archive-alist) :append)

         (setq pkgs (append pkgs (cdr archive-alist))))

       (package-initialize)

       (package-refresh-contents)

       (dolist (pkg pkgs)

         (package-install pkg)

         (require pkg))

       ,@body

       )))

That way, a user can just add something like below in their emacs bug reports:

(emacs-pkg-debug-setup '((("melpa" . "http://melpa.org/packages/") . (projectile)))

  (projectile-global-mode))

Then anyone can safe evaluate just that little form in a fresh emacs -Q session, and let the emacs-pkg-debug-setup macro handle the package-archives updating and package installation. The packages get installed to "/tmp/$USER/.emacs.d-debug/elpa/" by default.

--

--
Kaushal Modi