One of the console language settings disappears after system reboot

perl: warning: Falling back to a fallback locale (“en_US.UTF-8”).

I have to manually add it using the “export” command, but this only works until a reboot

What are the commands you used to set it? Have you tried to make these settings from root? TAKE NOTE - I am only guessing as this topic is very vague

Message appears during system upgrade yay -Syyu

perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
perl: warning: Setting locale failed.
LANGUAGE = (unset),
perl: warning: Please check that your locale settings:
are supported and installed on your system.
LANG = “en_US.UTF-8”
are supported and installed on your system.
perl: warning: Falling back to a fallback locale (“en_US.UTF-8”).
perl: warning: Falling back to a fallback locale (“en_US.UTF-8”).
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
LANGUAGE = (unset),
LC_ALL = (unset),

This part sticks out to me, what is your system locale set to?

locale
locale: Cannot set LC_ALL to default locale: No such file or directory

I’d suggest reading through this
https://wiki.archlinux.org/title/locale
I haven’t made any changes to mine, though I should as the english automatically loads as english US but here in Oz we us english GB - and this is what I thought I had set

locale -a
C
C.UTF-8
en_US.utf8
POSIX

and

locale
locale: Cannot set LC_ALL to default locale: No such file or directory

https://bbs.archlinux.org/viewtopic.php?id=257376

Closest issue I can find to this right now, really tired (hope it gives you some starting points)

locale-gen
Generating locales...
  en_US.UTF-8... done
Generation complete.
[root@pal ~]# locale -a
C
C.UTF-8
en_US.utf8
POSIX
[root@pal ~]# locale 
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.UTF-8
.....
LC_ALL=

I complete the line LC_ALL=en_US.UTF-8 with command “export” and this works until the system is rebooted.

Not too sure then, give it time someone more knowledgable than me will come along

And when I log into another computer via ssh when LC_ALL is not specified and launch mc , I see the following picture (There’s also a locale en_US.utf8)

Locale is not a command that set the locale, what’s the content of :

cat /etc/default/locale

and

cat /etc/locale.conf 

To set the locale use localectl :

localectl set-locale en_US.UTF-8

then check :

localectl status

I removed all from /etc/default/locale and left only en_US.UTF-8 in /etc/locale.conf. Besides English, there was another language that I manually changed and it gave such side effects. Now everything is all right

It’s all the fault of сalamares, who installs regional languages without asking when installing the system. Is it possible to disable this feature during system installation?To avoid this, you have to select the US region during installation and then adjust the time and etc to your region

No, the only languages that are generated during the install are en_US.UTF-8, which is the default system language, and the one you setup with Calamares, what’s in /etc/locale.gen ?

grep -v '^#' /etc/locale.gen

grep -v ‘^#’ /etc/locale.gen
en_US.UTF-8 UTF-8