when you get an error like this (seems to happen on all my fresh ubuntu installs)
perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_PAPER = "de_CH.UTF-8", LC_ADDRESS = "de_CH.UTF-8", LC_MONETARY = "de_CH.UTF-8", LC_NUMERIC = "de_CH.UTF-8", LC_TELEPHONE = "de_CH.UTF-8", LC_IDENTIFICATION = "de_CH.UTF-8", LC_MEASUREMENT = "de_CH.UTF-8", LC_TIME = "de_CH.UTF-8", LC_NAME = "de_CH.UTF-8", LANG = "en_US.UTF-8" are supported and installed on your system.
you need to simply generate the missing locae by runningn
locale-gen "de_CH.UTF-8"
problem solved ;)
localedef -v -c -i en_US -f UTF-8 en_US.UTF-8