gpg 2.2 and epa

[Paul Eggert]

Richard Stallman wrote:
> I tried installing gpg 2.2 some months ago, but Emacs master ceased to
> recognize when it was asking for a password.  Has anyone had success
> with this?

Emacs master works for me on my Ubuntu 18.04.1 desktop, where "gpg --version" 
reports gpg (GnuPG) 2.2.4 with libgcrypt 1.8.1.

Emacs master (like Emacs 26.1) delegates password handling to gpg2. That is, 
Emacs itself isn't responsible for reading passphrases; gpg2 does it for Emacs. 
On my desktop, when I am using Emacs and need a GPG passphrase, a window pops up 
(I assume generated by the GPG agent), and the agent remembers the key.

If you want to continue to type the passphrase into Emacs, here is a relevant 
20-message thread, dated 2016:

https://lists.gnu.org/archive/html/help-gnu-emacs/2016-02/msg00102.html

with the conclusion seeming to be "it's not worth the trouble".