Comment 0 for bug 1720422

Thunderbird 52 fails to build on armhf and s390x. (Firefox failed to build on armhf too until recently). Since Firefox doesn't build on s390x and s390x is not supported for Ubuntu Desktop, it looks like we should drop thunderbird on s390x.

$ reverse-depends -a s390x src:thunderbird
Reverse-Recommends
==================
* lxqt (for thunderbird) the dependency is satisfied:
 thunderbird | claws-mail | mutt
* ubuntu-mate-desktop (for xul-ext-gdata-provider)
* ubuntu-mate-desktop (for xul-ext-calendar-timezones)
* ubuntu-mate-desktop (for thunderbird)
* ubuntu-mate-desktop (for thunderbird-gnome-support)
* ubuntu-mate-desktop (for xul-ext-lightning)
* ubuntukylin-desktop (for thunderbird)
* ubuntukylin-desktop (for thunderbird-locale-zh-cn)
* ubuntukylin-desktop (for thunderbird-gnome-support)
* ubuntustudio-desktop (for thunderbird)
* unity-session (for thunderbird-gnome-support) arch:all
* xubuntu-desktop (for thunderbird)
* xul-ext-colorediffs (for thunderbird) arch:all

Reverse-Depends
===============
* cinnamon-desktop-environment (for thunderbird) the dependency is satisfied:
icedove | thunderbird | evolution | geary
* enigmail (for thunderbird) arch:all
* thunderbird-locale-dsb (for thunderbird) actually from src:thunderbird
* thunderbird-locale-zh-hans (for thunderbird) actually from src:thunderbird
* thunderbird-locale-zh-hant (for thunderbird) actually from src:thunderbird
* ubuntu-defaults-zh-cn (for thunderbird-locale-zh-cn) arch:all
* xul-ext-exteditor (for thunderbird) arch:all
* xul-ext-kwallet5 (for thunderbird)
* xul-ext-mozvoikko (for thunderbird) arch:all
* xul-ext-password-editor (for thunderbird) arch:all
* xul-ext-tbdialout (for thunderbird) arch:all
* xul-ext-torbirdy (for thunderbird) arch:all
* xul-ext-ublock-origin (for thunderbird) arch:all

$ reverse-depends -b src:thunderbird
No reverse dependencies found

The *ubuntu*-desktop metapackages just need to be rebuilt once thunderbird/s390x is removed.

That leaves source firefox-kwallet5 (xul-ext-kwallet5). We can rebuild that with a build-depends on firefox | thunderbird which will make it unbuildable on s390x.

Therefore please remove all the thunderbird binaries and xul-ext-kwallet5 from s390x.