Verified:
root@focal:~# dpkg-query -W libc6 libc6:amd64 2.31-0ubuntu9.2 root@focal:~# cp /etc/default/locale /tmp/locale root@focal:~# update-locale --locale-file /tmp/locale LANGUAGE = en_US.UTF-8 root@focal:~# diff -u /etc/default/locale /tmp/locale --- /etc/default/locale 2019-10-21 18:01:06.000000000 +0000 +++ /tmp/locale 2022-01-25 07:54:27.491679519 +0000 @@ -1 +1,2 @@ LANG=C.UTF-8 += root@focal:~# apt install libc6/focal-proposed libc-bin/focal-proposed locales/focal-proposed libc6-dev/focal-proposed libc6-dbg/focal-proposed libc-dev-bin/focal-proposed [...] root@focal:~# cp /etc/default/locale /tmp/locale root@focal:~# update-locale --locale-file /tmp/locale LANGUAGE = en_US.UTF-8 root@focal:~# diff -u /etc/default/locale /tmp/locale root@focal:~#
Verified:
root@focal:~# dpkg-query -W libc6 proposed libc-bin/ focal-proposed locales/ focal-proposed libc6-dev/ focal-proposed libc6-dbg/ focal-proposed libc-dev- bin/focal- proposed
libc6:amd64 2.31-0ubuntu9.2
root@focal:~# cp /etc/default/locale /tmp/locale
root@focal:~# update-locale --locale-file /tmp/locale LANGUAGE = en_US.UTF-8
root@focal:~# diff -u /etc/default/locale /tmp/locale
--- /etc/default/locale 2019-10-21 18:01:06.000000000 +0000
+++ /tmp/locale 2022-01-25 07:54:27.491679519 +0000
@@ -1 +1,2 @@
LANG=C.UTF-8
+=
root@focal:~# apt install libc6/focal-
[...]
root@focal:~# cp /etc/default/locale /tmp/locale
root@focal:~# update-locale --locale-file /tmp/locale LANGUAGE = en_US.UTF-8
root@focal:~# diff -u /etc/default/locale /tmp/locale
root@focal:~#