losing locale when running fcgi script

问题

I'm facing an issue with encoding in running a django app. I finally found out my django app has no locale set.

The weird thing is that I did set up the envvars file correctly. With this in envvars :

export APACHE_RUN_USER=www-data
export APACHE_RUN_GROUP=www-data
export APACHE_PID_FILE=/var/run/apache2.pid

## The locale used by some modules like mod_dav
export LANG=C
## Uncomment the following line to use the system default locale instead:
. /etc/default/locale

export LANG
locale

When I restart apache the locale command gets executed and I get correct fr_FR.UTF-8 settings for LANG and LC_*.

Now I set up a little test.fcgi script :

#!/usr/bin/python
def myapp(environ, start_response):
    start_response('200 OK', [('Content-Type', 'text/plain')])
    from commands import getoutput
    return ["%s"%getoutput("locale")]

from flup.server.fcgi import WSGIServer
WSGIServer(myapp).run()

when I run it with

sudo -u www-data test.fcgi

I get the correct locale settings as well. But whenever I access the script through a web browser, I get no locale settings :

LANG=
LC_CTYPE="POSIX"
LC_NUMERIC="POSIX"
LC_TIME="POSIX"
LC_COLLATE="POSIX"
LC_MONETARY="POSIX"
LC_MESSAGES="POSIX"
LC_PAPER="POSIX"
LC_NAME="POSIX"
LC_ADDRESS="POSIX"
LC_TELEPHONE="POSIX"
LC_MEASUREMENT="POSIX"
LC_IDENTIFICATION="POSIX"
LC_ALL=

How come Apache has the right setting but my fcgi script hasn't?