Bugzilla Bug 218147

I have LINGUAS="en de en_US en_GB" in my /etc/make.conf, and suddenly the
latest Thunderbird runs with German UI by default. Some investigation showed a
missing IUSE to be the reason. The order of LINGUAS is taken from the LINGUAS
variable, but it is filtered with the IUSE settings of the ebuild. Therefore,
the ebuild sees LINGUAS="de en_GB" and consequently sets de to be the default
UI language.

Simply adding linguas_en (and probably linguas_en_US as well) to the IUSE seems
to be the easiest workaround, as there are already some places in the ebuild
doing special handling for en.

My system is portage 2.1.5_rc3, LINGUAS="en de en_US en_GB". I guess the rest
of emerge --info should be unimportant.

Workaround for users hit by this bug: start with "thunderbird -UILocale en" or
change general.useragent.locale in your config editor or prefs.js

This bug seems to be hitting mozilla-firefox-2.0.0.14 for me as well.  Adding 
linguas_en fixes it there, too.

And why don't you set en_US before de?

Confirmed that I have the problem for mozilla-thunderbird as well.  Also, I
forgot to post my LINGUAS:

LINGUAS="en_US en pt_BR"

(Notice that I do have both en and en_US before pt_BR.)

Can you guys test with =portage-2.1.4*, in case its a portage regression?

(In reply to comment #2)
> And why don't you set en_US before de?

Wouldn't help, as en_US gets filtered due to missing IUSE as well, as seen from
the shortened LINGUAS in comment #0 or the case from comment #3.

Generally I'd expect every ebuild that understands en_US and also cares for
order to understand en as well, as there are probably many more people out
there giving only short language codes without country codes. I agree, though,
that putting all en_* before de would be more appropriate. Doesn't mater here,
though.

(In reply to comment #4)
> Can you guys test with =portage-2.1.4*, in case its a portage regression?

Yes, indeed portage 2.1.4 doesn't filter en.

From the portage-2.1.5_rc3.diff ChangeLog entry concerning pym/portage.py:
+  9853 zmedico  Bug #215016 - When transforming of USE flags to USE_EXPAND
+                variables, filter out flags that aren't considered to be part
+                of IUSE or implicit IUSE. This patch moves all IUSE dependent
+                code from config.regenerate() to config.setcpv(). (trunk
+                r9852)

There is also a large hunk on this in the diff.

Should be fixed now

*** Bug 218685 has been marked as a duplicate of this bug. ***