Re: bad epg.el+GPG2 behavior: unavoidable passphrase pinentry prompt

[Ted Zlatanov <tzz@lifelogs.com>]

On Mon, 30 Sep 2013 14:53:38 -0400 Stefan Monnier <monnier@IRO.UMontreal.CA> wrote: 

>> but with GPG 2.x that seems to be disabled and the pinentry prompt pops
>> up no matter what.

SM> What happens if you redirect stdin from /dev/null?

Same outcome.  Removing /usr/bin/pinentry is the only way to stop the
popup; if I put /usr/bin/pinentry back I get the curses or X popup no
matter what:

% echo x > /tmp/t
% mv /usr/bin/pinentry /usr/bin/pinentry.bak
% gpg --passphrase-fd=0 --decrypt authinfo.gpg  < /tmp/t
gpg: CAST5 encrypted data
gpg-agent[28972]: can't connect to the PIN entry module: IPC connect call failed
gpg-agent[28972]: command get_passphrase failed: No pinentry
gpg: problem with the agent: No pinentry
gpg: encrypted with 1 passphrase
gpg: decryption failed: No secret key

% mv /usr/bin/pinentry.bak /usr/bin/pinentry
% gpg --passphrase-fd=0 --decrypt authinfo.gpg  < /tmp/t
(pinentry query UGH)

Oh, I finally found a workaround!  No idea if it would work in the GnuPG
2.1 release Ueno-san mentioned because I can't find a 2.1, but this
worked for me with 2.0.20:

gpg --passphrase-fd=0 --batch --decrypt authinfo.gpg  < /tmp/t

This mode is not used in epg.el right now, so the popup keeps happening.

I can try to patch this myself but it seems, with the potential GnuPG
2.1 and the other pinentry developments mentioned by Ueno-san, that I
should leave this to him because I don't know the full story.  The
obvious fix here could break something else with the next release.

Should I open a bug, then, with the suggested workaround?  Or wait?  The
multiple popups are really annoying.

Thanks!
Ted