preseeded value of "locales/locales_to_be_generated"

[Derek Poon]

Andy,

I was just investigating this issue a few days ago, and came to the conclusion that Ubuntu 16.04 ignores debconf when it comes to selecting locales.  The /var/lib/dpkg/info/locales.config file was introduced between 14.04 and 16.04, and its presence causes /usr/share/debconf/frontend to ignore /var/lib/dpkg/info/locales.postinst, which used to do the debconf integration.

The /var/lib/dpkg/info/locales.config script, on the other hand, only reads its settings from /var/lib/locales/supported.d/local.  I have therefore devised this hook to use debconf to write out /var/lib/locales/supported.d/local.

hooks/updatebase.UBUNTU
==========================================================================
# In Ubuntu 16.04 (but not 14.04), the locales configuration mechanism has
# changed.  There is a /var/lib/dpkg/info/locales.config file, which
# overrides /var/lib/dpkg/info/locales.postinst and consults
# /var/lib/locales/supported.d/local instead of the debconf system.  (See
# the code in /usr/share/debconf/frontend that prefers locales.config.) This
# hook applies the debconf setting.  It must run after FAI's debconf task
# but before dpkg gets a chance to clobber debconf with an empty setting.

if [ ! -f "$target/var/lib/locales/supported.d/local" ]; then
    $ROOTCMD debconf --owner=locales sh -c '
        . /usr/share/debconf/confmodule
        db_version 2.0
        db_get locales/locales_to_be_generated &&
        mkdir -p /var/lib/locales/supported.d &&
        echo "$RET" > /var/lib/locales/supported.d/local' &&
    $ROOTCMD dpkg-reconfigure locales
fi

==========================================================================

I consider it to be a workaround for a bug.

Derek Poon
University of British Columbia



> On Jul 10, 2016, at 19:39, andrew bezella <abezella at archive.org> wrote:
> 
> hi -
> 
> i've been having some issues w/locales on a xenial system, installed
> from a jessie nfsroot with fai 5.1.  my initial problem was that i'd not
> been including the 'language-pack-en' but it still doesn't seem to be
> working as expected.
> 
> i'd logged https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1598326
> but at one point it appeared that might be a red herring.
> the locales excerpts from debconf.data ([2]) are: 
> locales locales/default_environment_locale select None
> locales locales/locales_to_be_generated multiselect en_US.UTF-8 UTF-8
> 
> it's unclear to me why the run of `/var/lib/dpkg/info/locales.config
> reconfigure 2.23-0ubuntu3` behaves as it does.  beyond the above
> "Substitution failed" error, while looking at the debug output i noticed
> other confusing bits.  e.g., after finding $target/etc/locale.gen empty,
> the locales.config script (via GEN_LOCALES and SELECTED_LOCALES
> variables)  appears to *un*set locales/locales_to_be_generated: 
> + SELECTED_LOCALES=
> + db_set locales/locales_to_be_generated 
> + _db_cmd SET locales/locales_to_be_generated 
> + _db_internal_IFS=     
> 
> + IFS= 
> + printf %s\n SET locales/locales_to_be_generated 
> + IFS=  
> 
> + IFS=
> read -r _db_internal_line
> debconf (developer): <-- SET locales/locales_to_be_generated 
> debconf (developer): --> 0 value set
> + RET=value set
> + return 0
> 
> similarly, it seems that the script tries to substitute the
> DEFAULT_LOCALES that it finds (from on-disk files) into
> locales/default_environment_locale (cf. the debconf error above) without
> regard to its existing value.
> 
> while investigating i did also find this unexpected bit during fai's
> debconf task (full logs[1]): 
> read -r _db_internal_line
> debconf (developer): <-- SUBST locales/default_environment_locale locales en_US.UTF-8
> debconf (developer): --> 100 Substitution failed
> + RET=100 Substitution failed
> + return 100
> 
> but i'm guessing some of my confusion there may have to do with: 
> DEBCONF_DB_OVERRIDE="File{$tmpdb readonly:true}"
> and its interaction with `dpkg-reconfigure`
> 
> because despite all the above, the resultant system ends up with the
> desired debconf settings: 
> locales locales/locales_to_be_generated multiselect     en_US.UTF-8 UTF-8
> locales locales/default_environment_locale      select  None
> 
> *however*, the on-disk /etc/locale.gen only has commented lines and
> while /etc/default/locale is empty when i set "None", it is also empty
> when i set locales/default_environment_locale to en_US.UTF-8 via fai's
> debconf.
> 
> then there's a bit that leads me back to that bug.  on the live system,
> attempting to noninteractively reconfigure locales again *un*sets
> locales/locales_to_be_generated (full output [3]): 
> ~# debconf-show locales
> * locales/locales_to_be_generated: en_US.UTF-8 UTF-8
> * locales/default_environment_locale: en_US.UTF-8
> ~# egrep -v ^\# /etc/locale.gen 
> 				[intentionally blank lines]
> 
> ~# cat /etc/default/locale 
> #  File generated by update-locale
> ~# DEBIAN_FRONTEND=noninteractive /usr/sbin/dpkg-reconfigure locales
> Generating locales (this might take a while)...
>  en_AG.UTF-8... done
>  en_AU.UTF-8... done
>  en_BW.UTF-8... done
>  en_CA.UTF-8... done
>  en_DK.UTF-8... done
>  en_GB.UTF-8... done
>  en_HK.UTF-8... done
>  en_IE.UTF-8... done
>  en_IN.UTF-8... done
>  en_NG.UTF-8... done
>  en_NZ.UTF-8... done
>  en_PH.UTF-8... done
>  en_SG.UTF-8... done
>  en_US.UTF-8... done
>  en_ZA.UTF-8... done
>  en_ZM.UTF-8... done
>  en_ZW.UTF-8... done
> Generation complete.
> ~# debconf-show locales
> * locales/locales_to_be_generated:
> * locales/default_environment_locale: en_US.UTF-8
> ~# egrep -v ^\# /etc/locale.gen 
> 
> 
> ~# cat /etc/default/locale 
> #  File generated by update-locale
> LANG=en_US.UTF-8
> 
> so at this point i believe i'm back to it being a bug of some sort in
> locales's dpkg wrappings.  notably, when `/usr/sbin/dpkg-reconfigure
> locales` is run *interactively* in place of the noninteractive call,
> "en_US.UTF-8 UTF-8" is *not* preselected; selecting it and completing
> the reconfigure results in what i would expect (full output [4]): 
> ~# debconf-show locales
> * locales/locales_to_be_generated: en_US.UTF-8 UTF-8
> * locales/default_environment_locale: en_US.UTF-8
> ~# egrep -v ^\# /etc/locale.gen 
> 
> 
> ~# cat /etc/default/locale 
> #  File generated by update-locale
> ~# /usr/sbin/dpkg-reconfigure locales
> Generating locales (this might take a while)...
>  en_AG.UTF-8... done
>  en_AU.UTF-8... done
>  en_BW.UTF-8... done
>  en_CA.UTF-8... done
>  en_DK.UTF-8... done
>  en_GB.UTF-8... done
>  en_HK.UTF-8... done
>  en_IE.UTF-8... done
>  en_IN.UTF-8... done
>  en_NG.UTF-8... done
>  en_NZ.UTF-8... done
>  en_PH.UTF-8... done
>  en_SG.UTF-8... done
>  en_US.UTF-8... done
>  en_ZA.UTF-8... done
>  en_ZM.UTF-8... done
>  en_ZW.UTF-8... done
> Generation complete.
> ~# debconf-show locales
> * locales/default_environment_locale: en_US.UTF-8
> * locales/locales_to_be_generated: en_US.UTF-8 UTF-8
> ~# egrep -v ^\# /etc/locale.gen 
> 
> 
> en_US.UTF-8 UTF-8
> ~# cat /etc/default/locale 
> #  File generated by update-locale
> LANG=en_US.UTF-8
> 
> if anyone has feedback/advice/thoughts, please lmk.  otherwise i think
> i'll be adding this to that bug report.
> 
> tia!
> 
> andy
> 
> 1 https://www.us.archive.org/~abezella/tmp/fai-debconf+debug.log
> 2 https://catalogd.archive.org/~abezella/tmp/debconf.data.txt
> 3 https://catalogd.archive.org/~abezella/tmp/noninteractive-dpkg-reconfigure+debug.log
> 4 https://catalogd.archive.org/~abezella/tmp/interactive-dpkg-reconfigure+debug.log
> 
> -- 
> andrew bezella <abezella at archive.org>
> Internet Archive
>