bug#20817: 25.0.50; Problems with upgrading of packages

[Mark Karpov]

After a recent fix, packages are still unavailable for me, but error
message has changed to:

  error in process filter: peculiar error: 404

I'm sorry that I didn't investigate the problem immediately. Previously,
it seemed like even when I start Emacs with -Q flag the problem is
there. Now, when I start it without my configuration file it works fine.

So, there is something in my configuration file that conflicts with the
recent changes. I have to say that it worked until now, so theoretically
it should work after the improvements too.

I've found out that this code suffices to break package
upgrading/displaying (all the stuff is quite trivial):

(setq
 package-selected-packages
 ;; I prefer setting it explicitly, I even filter arguments of
 ;; ‘package-install’ so it never adds anything to this list,
 ;; but that advice doesn't cause the problem
 '(ace-window
   aggressive-indent
   auctex
   avy
   buffer-move
   cider
   common-lisp-snippets
   fix-word
   flycheck
   flycheck-haskell
   ghc
   gitignore-mode
   haskell-mode
   ido-hacks
   ido-ubiquitous
   ido-vertical-mode
   magit
   markdown-mode
   multiple-cursors
   prolog
   rainbow-delimiters
   smartparens
   smex
   solarized-theme
   whole-line-or-region
   yasnippet))

(require 'package)

(add-to-list
 'package-archives '("melpa" . "http://melpa.milkbox.net/packages/";))

(package-initialize)

(unless package-archive-contents
  (package-refresh-contents))

;; I know about new function ‘package-install-selected-packages’, but
;; I don't like it, it asks questions and I don't remember now, but
;; there were other problems with it, so I do install stuff manually

(dolist (package package-selected-packages)
  (unless (package-installed-p package)
    (package-install package)))

You can now build Emacs, evaluate buffer with this code and try it. The
problem can be further narrowed, I'm sure, but I have no idea what's
going on under the hood, so you can do it better than me. Tell me if
this code doesn't reproduce the problem for you.

Also, answering question from the previous email,
‘package-refresh-contents’ works fine.