bug#25947: 26.0.50; EasyPG does not honor customized epg-gpg-program

[Jens Lechtenboerger]

Hi there,

I'm experimenting with Emacs on Qubes OS with Split GPG [0], where I
need to redirect invocations of gpg to qubes-gpg-client-wrapper.
However, customizing epg-gpg-program does not work, recipe from
'emacs -Q':

Check value of epg-gpg-program; in my case, I see gpg2:
C-h v epg-gpg-program

Eval the following:
(setq epg-debug t)
(customize-set-variable 'epg-gpg-program "/bin/echo")

Invoke some EasyPG operation, e.g., encrypt a fresh file:
C-x C-f test.gpg

At this point, the debug buffer " *epg-debug*" shows that
/usr/bin/gpg was invoked for decryption.  Note that this is neither
gpg2 (my machine's default) nor /bin/echo (my customization).

Continue:
M-x spook
C-x C-s
A buffer for key selection opens.  It doesn't matter whether I
select a public key (if there is one) or go for symmetric
encryption.  Leave that buffer:
C-c C-c
Enter a Passphrase (e.g., "test") twice in case of symmetric
encryption.

Notice that an encrypted file has been created.
Buffer " *epg-debug*" shows that /usr/bin/gpg was used for
encryption, not /bin/echo.  It doesn't matter whether I use
customize or setq on epg-gpg-program.

As a workaround, I've got the following in my .emacs:
(require 'epg-config)
(setq epg-gpg-program "/usr/bin/qubes-gpg-client-wrapper")
(push (cons 'OpenPGP (epg-config--make-gpg-configuration epg-gpg-program))
      epg--configurations)

Best wishes
Jens


In GNU Emacs 26.0.50 (build 1, x86_64-unknown-linux-gnu, X toolkit, Xaw3d 
scroll bars)
 of 2017-02-24 built on debian-8
Repository revision: 91932fff1ded8ed3b4d39dd06891f26960153b9e

[0] https://www.qubes-os.org/doc/split-gpg/