Bug#845781: libgnupg-interface-perl: in-band passphrases do not work with gpg2

[Dominic Hargreaves]

Package: libgnupg-interface-perl
Version: 0.52-5
Severity: important
Forwarded: https://rt.cpan.org/Public/Bug/Display.html?id=102651
X-Debbugs-Cc: dkg at fifthhorseman.net

As documented in the discussions at #839580 this package doesn't
support in-band passphrases with gpg2. This was worked around in 
RT to use gpg1 again.

This is fixed in 0.52-6 which is currently in experimental, but
this isn't backwards-compatible to earlier versions of gpg due to [1].

That said, it's probably preferable to upload this to unstable once it's
been tested a bit more than to rely on gpg1 for the stretch cycle.

dkg's suggestion on the upstream mailing list looks plausible:

"One way to resolve this would be to add --pinentry-mode=loopback as a
dummy no-op parameter to classic and modern.  This doesn't help for old
installations, of course, but if someone can upgrade within a given
series, it would at least let the bindings work."

dkg - should we just go ahead and do this in gnupg1 in Debian?
This would AFAICT be preferable to a coordinated upgrade between
libgnupg-interface-perl and RT (and I would guess this problem would
arise in other places too).

Thanks for all your work on this so far!

Dominic.

[1] <https://lists.gnupg.org/pipermail/gnupg-devel/2016-October/031800.html>