Hello.

When I installing this Debian GNU/Linux trixie system, I have selected
'Chinese (Traditional)' in the '[!!] Select a language' screen, which is the
first step in the debian-installer, then in the next screen of selecting my
location, I selected 'China'. After this point, the UI language of the
installer completely switched to Simplified Chinese, and the final installed
system has 'LANG=zh_CN.UTF-8', which is completely against my initial
selection.

In my understanding, the location selection should only provide a hint for the
default time zone and the default network APT sources; it shouldn't change the
language, as my preferred language has already been set by the first screen.

Hi,

WHR <whr@rivoreo.one> wrote (Mon, 06 Jul 2026 11:40:47 +0800):
However, Chinese seems to be a corner case here.

But I think there is a way, how you can get, what you want:
Could you try to start the installer in the expert mode (so when booting
the installer ISO, select "Advanced options" and then "Graphical expert
install" or "Expert install").

Then you are prompted to choose language, country and system locale.
That way, you can choose
	Chinese (Traditional)
	China
	zh_TW.UTF-8

(The third choice is the key here!)


That should give you what you want.

Can you confirm this?


Holger

'Chinese (Traditional)' in the '[!!] Select a language' screen, which is
the
installer completely switched to Simplified Chinese, and the final
installed
selection.
the installer ISO, select "Advanced options" and then "Graphical expert
install" or "Expert install").
way, you can choose

Yes. I just tested debian-installer with expert mode, in a virtual machine.
An additional screen that allows me selecting the locale variant appeared,
which includes all the supported Chinese variants, including zh_TW.UTF-8.

Hi Holger Wansing,

I want to let you know that my previous message was rejected by your email
system:

<hwansing@mailbox.org>: host mx4.mailbox.org[80.241.60.217] said: 554 5.7.1
    Service unavailable; Client host [188.245.113.95] blocked by RBL;
http://www.barracudanetworks.com/reputation/?pr=1&ip=188.245.113.95 (in
    reply to RCPT TO command)

"WHR" <whr@rivoreo.one> wrote (Wed, 8 Jul 2026 06:26:43 -0000):

So I'm tagging this bug wontfix.

Thanks for confirmation!


Holger

Hi,

Holger Wansing <hwansing@mailbox.org> (2026-07-08):

Yes, it's great to have a confirmed workaround, and yes, that's a tricky
situation, as we're running into some kind of conflict… For the record,
we start with language set to zh_TW:zh (and zh_TW.UTF-8 as default
locale) after picking Chinese (Traditional), which get replaced with
zh_CN:zh_TW:zh (and zh_CN.UTF-8) after picking the default entry (3rd
from the top).

I'm wondering whether it would make sense to special case this, making
sure to keep zh_TW:zh (and zh_TW.UTF-8)… After all, if someone wanted
zh_CN (and zh_CN.UTF-8), why would they pick Chinese (Traditional) in
the first place?

Alternatively, we could try and detect this weird situation and adjust
the supported locale priority to make sure one has a chance to either
add zh_TW.UTF-8 to zh_CN.UTF-8 or replace the latter entirely, but that
wouldn't change the fact zh_CN would be used instead of zh_TW for the
entirety of the installer's runtime?

Just in case someone wants to play around, here's a reminder of which
country is which:

    Template: localechooser/shortlist/zh_TW
    Type: select
    Choices-C: CN, SG, TW, HK, other
    Choices: China, Singapore, Taiwan, Hong Kong, other
    Choices-zh_TW.UTF-8: 中國, 新加坡, 臺灣, 香港, 其它


Cheers,

I will have to remember to run the debian-installer in expert mode in the
future then.