Xubuntu 20.04 has incomplete language support of offline install

[emptythevoid]

Xubuntu daily 20200309 will result in an installation that popups up "incomplete language support" on boot if no network/download updates is selected during installation.

Tested on a Dell Latitude 3470.

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1866659

[Dimitri John Ledkov (xnox)]

Which language was used?

[emptythevoid (emptythevoid)]

Sorry, that would've been useful info. English (US). I haven't tested a recent daily build,so I don't know if this is still a problem or not.

[Guilherme Campos (cheker)]

It still happens. English (US) was my selected system language

[Steve Langasek (vorlon)]

If there are packages missing for language support, this is a question of the per-flavor image seed, not of ubiquity itself. Reassigned.

[Sean Davis (bluesabre)]

For English (US) on hirsute, here's the missing packages:

hyphen-en-gb
libreoffice-help-en-us
libreoffice-l10n-en-za
gimp-help-en
thunderbird-locale-en
libreoffice-help-en-gb
wbritish
thunderbird-locale-en-gb
libreoffice-l10n-en-gb
hunspell-en-za
hunspell-en-au
mythes-en-au
hyphen-en-us
thunderbird-locale-en-us
hyphen-en-ca
mythes-en-us
hunspell-en-gb
hunspell-en-ca

It looks like ubuntu automatically includes these files for a select number of languages.
https://people.canonical.com/~ubuntu-archive/seeds/ubuntu.hirsute/ (see the languages directory).

Should Xubuntu do the same?