caching of passphrases for symmetrically encrypted files

[Jim Gomi]

Since I upgraded to emacs 25.1.1 under Fedora 24, the caching of
passphrases for symmetrically encrypted files  has stopped working.

According to the documentation, 
https://www.gnu.org/software/emacs/manual/html_mono/epa.html#Caching-Pa
ssphrases
I can either use GnuPG 1.4, or configure gpg-agent. But I cannot get
either of these to work.

1) Using GnuPG 2.1.13
I tried adding this to ~/.gnupg/gpg-agent.conf:

allow-emacs-pinentry

but I am still asked to retype the passphrase twice when saving the
file.
Is there something else I should do?


2) Using GnuPG 1.4 
I tried adding this to my .emacs file:

(setq epg-gpg-program "/usr/bin/gpg")
(setenv "GPG_AGENT_INFO" nil)
(setq epa-file-cache-passphrase-for-symmetric-encryption t)

but it had no effect.
/usr/bin/gpg is the GnuPG 1.4 executable.