Arch Linux

I can confirm the problem,

translations are missing in the package

would be nice to make these translations for calendar work again.

I have worked on a new PKGBUILD which downloads all Lightning translations from the Mozilla source code repository and packages them as .xpi language packs. Could you please merge it?

Unfortunately that looks like the worst of both worlds: having to clone all the l10n repositories but still downloading prebuilt langpacks. It also looks rather fragile.

I know - the underlying issue is that the Lightning resources are not included in the default language packs provided by Mozilla. They instead chose to have the build system generate multiple versions of the extension at compile time (on request), one for each language (at least on official Windows builds).

I've searched the Arch and Mozilla bug trackers in depth and I think there are two possible solutions to this:
1) ask Mozilla to bundle the Lightning translations with the Thunderbird language packs;
2) rebuild the language packs ourselves (see e.g. https://bugs.archlinux.org/task/50219#comment149601).

I think the first solution is (obviously) preferable; in case it is rejected by upstream, would the second proposal be acceptable to you?

Yes; I'd rather not do it but if Mozilla can't fix the langpacks I don't see any other option.

I have requested feedback in https://bugzilla.mozilla.org/show_bug.cgi?id=1266696#c10, I'll add a comment here as soon as I've got a reply.

Problem still exists in
extra/thunderbird 60.0-3 [Installiert]
extra/thunderbird-i18n-de 60.0-2 [Installiert]

Looks like Language Pack and Main Application Package does not match. :(

Those problems around the internationalisation looks very unprofessional to us.

Edit: typo

Aalso Occours on matching version numbers.
extra/thunderbird-i18n-de 60.0-2 [Installiert]
local/thunderbird 60.0-2 [Installiert]

For those who might be interested, it's possible to create a package for your language based on this gist https://gist.github.com/progandy/ce857358c4f3b8eb09887a085e4bea30

As a workaround, you can delete Lightning in Thunderbird and then install it again through extension manager.

A waiting solution :

Download the latest Linux version of Thunderbird for your language (french for me) from the Thunderbird site.

Extract the .tar.bz2 archive, and in the thunderbird/distribution/extensions directory, you find the .xpi package for the Lightning extension

Replace the .xpi package in .thunderbird/xxxxxxxx.default-release/extensions/ by the one you just download and it works fine (68.1 TB and 68.1 lightning)

Defect: extra/thunderbird-i18n-de 68.1.0-1 [Installiert] German language pack for Thunderbird
Defect: extra/thunderbird 68.1.0-1 [Installiert] Standalone mail and news reader from mozilla.org

Those problems around the internationalisation looks very unprofessional to us.

It should be fixed.

This is no longer relevant, as the translations are now provided by Thunderbird itself:

From Thunderbird 74 onwards Lightning does not exist as a separate add-on but is integrated into Thunderbird.

https://developer.mozilla.org/en-US/docs/Mozilla/Calendar/Calendar_Versions

so this can be closed?

Well, I guess, if we'll have a new thunderbird-package (78.3.1?), we should look on this bug again, but I think it can be closed after the update. But at the moment we are still on 68, so it can't be closed now.

I think this can be closed as the Thunderbird package is now at version 78+