Hi, I read #361091 and noticed that after my 2nd time of apt-get upgrade, the LANG variable was commented out in /etc/default/locale.
Also, I think that a warning somewhere that the variables LANG and LANGUAGE have been moved from /etc/environment to /etc/default/locale, would be more than welcome. Without the bug, I wouldn't have noticed it and might have tried to activate back the variables in /etc/environment at a later point, with possible side effects and strange behaviours. Eric