Bug#784372: libx11-data: locale.alias has "C.UTF-8 -> en_US.UTF-8" - but en_US not installed

[jmullee <jmullee@yahoo.com>]

Package: libx11-data
Version: 2:1.6.2-3
Severity: normal
Tags: l10n

Dear Maintainer,

troubleshooting an unrelated - gnome-terminal not starting -
I found this line in

/usr/share/X11/locale/locale.alias
   C.UTF-8      en_US.UTF-8


I have no en_US locale set up, only en_IE.

I decided to replace it with this, to continue:
   C.UTF-8      C




-- System Information:
Debian Release: 8.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

-- debconf information:
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = (unset),
	LC_ALL = (unset),
	LC_TIME = "en_IE.utf8",
	LC_MONETARY = "en_IE.utf8",
	LC_MEASUREMENT = "en_IE.utf8",
	LC_NUMERIC = "en_IE.utf8",
	LC_PAPER = "en_IE.utf8",
	LANG = "en_GB.utf8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory

-- debsums errors found:
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = (unset),
	LC_ALL = (unset),
	LC_TIME = "en_IE.utf8",
	LC_MONETARY = "en_IE.utf8",
	LC_MEASUREMENT = "en_IE.utf8",
	LC_NUMERIC = "en_IE.utf8",
	LC_PAPER = "en_IE.utf8",
	LANG = "en_GB.utf8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
debsums: changed file /usr/share/X11/locale/C/XLC_LOCALE (from libx11-data package)
debsums: changed file /usr/share/X11/locale/locale.alias (from libx11-data package)