This is a copy from bug report at: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823555,


Despite the fact that I have org.gnome.Platform.Locale installed, I have issues when running Pitivi with LANG set to fr_FR.UTF-8

Following these instructions to install Pitivi daily bundle through 
xdg-app [1] and trying to run it, I get an error message relative locale 
despite the fact that org.gnome.Platform.Locale is installed :

"./pitivi-xdg-app

==========
Updating pitivi
==========

-> Updating org.gnome.Platform 3.20

1 metadata, 0 content objects fetched; 313 B transferred in 3 seconds
-> Updating org.gnome.Platform.Locale

1 metadata, 0 content objects fetched; 313 B transferred in 2 seconds
-> Updating org.pitivi.Pitivi master...


Couldn't set locale. /app/share/locale unsupported locale setting
Couldn't set locale. /app/share/locale unsupported locale setting

(pitivi:2): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.

** (pitivi:2): WARNING **: Couldn't connect to accessibility bus: Failed 
to connect to socket /tmp/dbus-CQ7da3CMbG: Connection refused
Traceback (most recent call last):
  File "/app/bin/pitivi", line 147, in <module>
    _check_requirements()
  File "/app/bin/pitivi", line 128, in _check_requirements
    if not check_requirements():
  File "/app/lib/pitivi/python/pitivi/check.py", line 276, in 
check_requirements
    print((_("Missing soft dependency:")))
UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in 
position 1: ordinal not in range(128)"


Running "$ LANG=fr_FR.UTF-8 xdg-app run org.pitivi.Pitivi" also failed :

"Couldn't set locale. /app/share/locale unsupported locale setting
Couldn't set locale. /app/share/locale unsupported locale setting

(pitivi:2): Gtk-WARNING **: Locale not supported by C library.
	Using the fallback 'C' locale.

** (pitivi:2): WARNING **: Couldn't connect to accessibility bus: Failed 
to connect to socket /tmp/dbus-CQ7da3CMbG: Connection refused
Traceback (most recent call last):
  File "/app/bin/pitivi", line 147, in <module>
    _check_requirements()
  File "/app/bin/pitivi", line 128, in _check_requirements
    if not check_requirements():
  File "/app/lib/pitivi/python/pitivi/check.py", line 276, in 
check_requirements
    print((_("Missing soft dependency:")))
UnicodeEncodeError: 'ascii' codec can't encode character '\xe9' in 
position 1: ordinal not in range(128)"


Running "$ xdg-app install --user gnome org.gnome.Platform.Locale 3.20" 
says :
"error: Runtime org.gnome.Platform.Locale, branch 3.20 is already installed"


See also the result of :
"$ xdg-app run --command=bash --filesystem=xdg-download org.pitivi.Pitivi
bash-4.3$ locale
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
LANG=fr_FR.utf8
LC_CTYPE="fr_FR.utf8"
LC_NUMERIC="fr_FR.utf8"
LC_TIME="fr_FR.utf8"
LC_COLLATE="fr_FR.utf8"
LC_MONETARY="fr_FR.utf8"
LC_MESSAGES="fr_FR.utf8"
LC_PAPER="fr_FR.utf8"
LC_NAME="fr_FR.utf8"
LC_ADDRESS="fr_FR.utf8"
LC_TELEPHONE="fr_FR.utf8"
LC_MEASUREMENT="fr_FR.utf8"
LC_IDENTIFICATION="fr_FR.utf8"
LC_ALL="


Whereas running $ LANG=en_US.UTF-8 xdg-app run org.pitivi.Pitivi works 
(=Pitivi starts)


FWIW I'm running Linux HAL 4.5.0-2-amd64 #1 SMP Debian 4.5.2-1 
(2016-04-28) x86_64 GNU/Linux & libc6 2.22-7


Thanks !