[Debconf-devel] Bug#543367: debconf: Dialog frontend can't start subshell

[Matthew Gabeler-Lee]

Package: debconf
Version: 1.5.27
Severity: normal


When attempting to resolve issues with a new config file in a package
upgrade, the dialog (whiptail) frontend for some reason cannot start a
subshell to examine the situation.  The screen flashses and instantly
returns to the menu of choices.

After mucking about a bunch, I managed to find that it was printing an error
message: "No terminal, and no DISPLAY set, can't fork shell."  Of course,
there was no pause to let anyone read that message, so it was effectively
invisible.

This is happening to me on every config file that gets the "do you want to
use the new package maintainer's version" set of questions.

This is happening running from apt, within screen, if that matters.

-- System Information:
Debian Release: squeeze/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.30.5-1 (SMP w/2 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/bash

Versions of packages debconf depends on:
ii  debconf-english               1.5.27     small footprint English-only debco
ii  perl-base                     5.10.0-25  minimal Perl system

Versions of packages debconf recommends:
ii  apt-utils                     0.7.22.2   APT utility programs

Versions of packages debconf suggests:
pn  debconf-doc               <none>         (no description available)
ii  debconf-utils             1.5.27         debconf utilities
ii  dialog                    1.1-20080819-1 Displays user-friendly dialog boxe
pn  libgnome2-perl            <none>         (no description available)
pn  libnet-ldap-perl          <none>         (no description available)
pn  libqt-perl                <none>         (no description available)
pn  libterm-readline-gnu-perl <none>         (no description available)
pn  perl                      <none>         (no description available)
ii  whiptail                  0.52.10-4      Displays user-friendly dialog boxe

-- debconf information:
  debconf-apt-progress/title:
  debconf-apt-progress/info:
* debconf/priority: low
  debconf-apt-progress/preparing:
  debconf-apt-progress/media-change:
* debconf/frontend: Dialog