Note: This one may not affect you at all, if you own a MacBook with an English keyboard layout (and corresponding native language settings).
I however, bought a MacBook Pro with a German keyboard layout, and when using, for example ‘git pull’ on the command line I got this message:
$git pull perl: warning: Setting locale failed. perl: warning: Please check that your locale settings: LANGUAGE = (unset), LC_ALL = (unset), LC_CTYPE = "UTF-8", LANG = (unset) are supported and installed on your system. perl: warning: Falling back to the standard locale ("C").
I added this to my .bash_profile:
export LC_CTYPE=en_US.UTF-8 export LC_ALL=en_US.UTF-8
Problem gone — thanks to the folks at spindicator.com who solved this problem already.
Note, that you may want to put in other values, depending on your language preferences.