ELPA list is missing markdown-mode according to list-packages

Question

I'm trying to install markdown-mode using instructions on https://jblevins.org/projects/markdown-mode/, according to which I put into my init.el file

(require 'package)
(add-to-list 'package-archives
         '("melpa-stable" . "https://stable.melpa.org/packages/"))
(package-initialize)

and evaluating it, then evaluating

M-x package-install RET markdown-mode RET

but it gives the message, "[Not found]".

I tried package-refresh-contents but it didn't fix the problem. Also, the list returned by package-list-packages doesn't contain "markdown".

I've spent about an hour googling and reading but haven't found a solution so far.

I'm using Aquamacs 3.4 GNU Emacs 25.3.50.1, which "Check for updates…" claims is the current version. (I guess there's a delay between Emacs releases and downstream integration; hopefully my issue is not version-specific.) This distribution has some built-in markdown functionality but not (apparently) markdown-mode. Also, somewhere I read that there are additional packages (markdown2 and a couple of others) that I'd also like to try but which are likewise missing from my list-packages.

Answer 1

Every time this has happened to me, it's because you are trying to install an outdated package (i.e. the package has been updated in melpa, but not on your system, so you are asking melpa for an old package).

Try M-x: list-packages and it should be solved. (it will also inform you if you have any packages to update with u and execute with x.

Hope this helps.

Answer 2

I finally figured out a solution, and it's simple.

Tl;dr:

1. Configure by editing ~/Library/Preferences/Aquamacs Emacs/Preferences.el as opposed to ~/init.el, which is where I had been hacking before. Aquamacs appears to ignore it.

2. I configured startup like this:

(setenv "PATH" (concat "~/bin.sh:/usr/local/bin:" (getenv "PATH")))
(require 'gnutls)
(add-to-list 'gnutls-trustfiles "/usr/local/etc/openssl/cert.pem")
(require 'package)
(add-to-list 'package-archives '("melpa-stable" . "https://stable.melpa.org/packages/"))
(package-initialize)

(That startup file might be messy in ways that I don't recognize because I'm new to emacs and elisp. In particular, I didn't know whether `(package-initialize)` belonged after each of the `(require)`s or just the last one.)

The longer story:

It might also be significant to note some of the steps I took prior to stumbling across the present solution, as they affected the state of the system. In particular, history | grep brew reveals

1718  brew install gnutls
1719  brew upgrade gnutls
1722  brew link --overwrite --dry-run gnupg
1723  brew link  gnupg
1726  sudo brew services start unbound
1727  brew install gnutls-cli
1729  brew install libffi
1730  brew link libffi
1734  brew uninstall libffi
1735  brew install libffi
1737  brew install libressl

I suspect that some of these are relevant because my solution only works when /usr/local/bin is present in PATH (the first line of Preferences.el).

I apologize that this answer is more recipe than insight but I hope it can help someone.

Thanks to all who engaged me on this question, especially @Tobias for pointing me in the direction of the TLS bug; also for the links, which taught me to look in the Messages buffer. I found the part with the cert.pm file in a short post by Stewart V. Wright on Vifortech Solutions' blog about this very problem but not specific to Aquamacs. The first line (the one that prepends to PATH) is from.