Hi,
having run into this issue, I have figured out why locales behaves unexpectedly.
Here's a snippet to show the issue:
--->8------>8------>8------>8------>8------>8------>8------>8------>8---
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree# apt install locales
Installing:
locales
Summary:
Upgrading: 0, Installing: 1, Removing: 0, Not Upgrading: 1
Download size: 0 B / 3902 kB
Space needed: 16.1 MB / 3378 MB available
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based
frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 79,
<STDIN> line 1.)
debconf: falling back to frontend: Readline
Preconfiguring packages ...
Selecting previously unselected package locales.
(Reading database ... 27044 files and directories currently installed.)
Preparing to unpack .../locales_2.39-6_all.deb ...
Unpacking locales (2.39-6) ...
Setting up locales (2.39-6) ...
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based
frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 79.)
debconf: falling back to frontend: Readline
Generating locales (this might take a while)...
Generation complete.
Processing triggers for man-db (2.12.1-2) ...
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree# cat << EOF |
debconf-set-selections
locales locales/default_environment_locale select en_US.UTF-8
locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8
EOF
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree# debconf-get-selections |
grep -P ^locales
locales locales/default_environment_locale select en_US.UTF-8
locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree# dpkg-reconfigure
--frontend=noninteractive locales
Generating locales (this might take a while)...
Generation complete.
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree# debconf-get-selections |
grep -P ^locales
locales locales/default_environment_locale select None
locales locales/locales_to_be_generated multiselect
root@sid:/tmp/autopkgtest.3hIrFA/build.AZ6/real-tree#
--->8------>8------>8------>8------>8------>8------>8------>8------>8---
As you can see above, I'm setting the debconf selections first, verifying that
they're correctly set, then run dpkg-reconfigure to let the reconfigure
mechanism run it's course. However, instead of correctly setting the
/etc/locale.gen and /etc/locale.conf to the debconf selections, those values are
reverted to the defaults. Interestingly, if the order of the "apt install
locales" and the debconf-set-selections command are reversed, it correctly sets
the locale.
The reason is how /var/lib/dpkg/info/locales.config is run. Here's the relevant
code snippet from this file:
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# Get the list of selected locales from /etc/locale.gen
if [ -e /etc/locale.gen ]; then
if [ -L $LG ] && [ "$(readlink $LG)" = "/usr/share/i18n/SUPPORTED" ]; then
SELECTED_LOCALES="All locales"
else
SELECTED_LOCALES="$(echo "$GEN_LOCALES" | sort -u | tr '\n' ',' | sed
-e 's/, */, /g' -e 's/, *$//g')"
fi
db_set locales/locales_to_be_generated "$SELECTED_LOCALES"
fi
DEFAULT_ENVIRONMENT="$(cat $LEGACY_EE $EE 2>/dev/null | awk '/^LANG=/
{gsub("\"", ""); sub("LANG=", ""); lang=$0;} END {print lang}')"
DEFAULT_ENVIRONMENT="$(convert_locale "$DEFAULT_ENVIRONMENT")"
if [ -n "$SUPPORTED_LOCALES" ] && [ -n "$DEFAULT_ENVIRONMENT" ]; then
if echo "$SUPPORTED_LOCALES" | grep -q -e "\b$DEFAULT_ENVIRONMENT\b" ; then
db_set locales/default_environment_locale "$DEFAULT_ENVIRONMENT"
fi
fi
--->8------>8------>8------>8------>8------>8------>8------>8------>8---
So when /etc/locale.gen exists, this file is read, and then the settings in the
debconf database overwritten by those value. So once debconf is installed,
there's no programmatic way via debconf to change the locale. A workaround is
template the files /etc/locale.gen and /etc/locale.conf and then run
dpkg-reconfigure locales.
This however seems counterintuitive to me, as practically all other packages
using debconf have the debconf database as authoritative data from which the
config is written (e.g. apt-cacher-ng, ca-certificates, console-setup, iproute2,
grub-efi-amd64, grub-pc, postfix, tzdata, wireshark-common, to name a few).
Neither /etc/locale.gen, nor /etc/locale.conf are marked as conffiles, so they
shouldn't edited by users, and neither be preserved, nor authoritative on the
matter. As such, I'm raising the bug severity.
I propose to remove the shown code lines from locales.config. This would make
any debconf selections authoritative again.
A compromise would be to add another debconf option that decides on which side
is authoritative (either config file, or debconf), but IMHO that adds complexity
without much benefit.
Regards,
Lee
