From helmut at subdivi.de  Wed Apr  2 10:55:46 2025
From: helmut at subdivi.de (Helmut Grohne)
Date: Wed, 2 Apr 2025 11:55:46 +0200
Subject: [Debconf-devel] Bug#1101919: Use of uninitialized value in
 concatenation (.) or string at /usr/share/perl5/Debconf/Config.pm line 23.
Message-ID: <20250402095546.GA2048302@subdivi.de>

Package: debconf
Version: 1.5.91
Severity: wishlist
File: /usr/share/perl5/Debconf/Config.pm

Hi Colin,

a while back I reported an uninitialized value in Config.pm (not sure 
what the context was), but now I'm seeing it again in the code path 
added.

...
Preparing to unpack .../libc6_2.41-6_arm64.deb ...
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/Config.pm line 23.
Unpacking libc6:arm64 (2.41-6) ...
...
Setting up libc6:arm64 (2.41-6) ...
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/Config.pm line 23.
Setting up mawk (1.3.4.20250131-1) ...
...
Setting up debconf (1.5.91) ...
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/Config.pm line 23.
Setting up libpam0g:arm64 (1.7.0-3) ...
Use of uninitialized value in concatenation (.) or string at /usr/share/perl5/Debconf/Config.pm line 23.
Setting up libpam-modules-bin (1.7.0-3) ...
...
Unpacking libdebconfclient0:arm64 (0.278) ...
Selecting previously unselected package base-passwd.
Preparing to unpack .../base-passwd_3.6.7_arm64.deb ...
Unpacking base-passwd (3.6.7) ...
Selecting previously unselected package init-system-helpers.
...
Setting up base-passwd (3.6.7) ...
...

This is part of mkosi-initrd output. The late configuration of 
base-passwd strikes as odd. Looking into the source, the right side of 
the concatenation is a bare string, so it likely is the left side 
calling getpwuid that produces undef here.

Do you consider that a bug in debconf? An option would be skipping any 
~/.debconfrc if neither DEBCONF_SYSTEMRC is set nor getpwuid returns 
somethig sensible?

If you consider this unreasonable, we should likely discuss the 
semantics of bootstrap e.g. on the debian-cross at l.d.o list before 
reaching a conclusion of bugginess in mkosi. The ordering has been a 
recurring topic.

Helmut