[valemon]

With almost any application I launch I get the following:

gdk-warning **: locale not supported by C library

locale output

locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannotset LC_MESSAGES to default locale: No such file or directory
locale: Cannotset LC_ALL to default locale: No such file or directory
LANG=en_US.UTF8
LC_CTYPE="en_US.UTF8"
LC_NUMERIC="en_US.UTF8"
LC_TIME="en_US.UTF8"
LC_COLLATE=C
LC_MONETARY="en_US.UTF8"
LC_MESSAGES="en_US.UTF8"
LC_PAPER="en_US.UTF8"
LC_NAME="en_US.UTF8"
LC_ADDRESS="en_US.UTF8"
LC_TELEPHONE="en_US.UTF8"
LC_MEASUREMENT="en_US.UTF8"
LC_IDENTIFICATION="en_US.UTF8"
LC_ALL=

Any clues?

[Thrillhouse]

Open up /etc/locale.gen as root and uncomment the entries for the locale you want to use. Save and close then run locale-gen as root. Restart X and you should be good.

ArchWiki :: Configuring locales - ArchWiki

[valemon]

Thanks, this one did it. One more question, I exported en_US.UTF-8 and the output of locale command says en_US.UTF8. Why is that?

[Thrillhouse]

The locale command tells you which locale you're using so if you uncommented en_US.UTF8, ran locale-gen and then locale and it showed you en_US.UTF8 then that tells you that everything came off successfully and that you're using that locale.