Today I was running through the motions of getting another VPS server setup with Ubuntu 8.0.4 86_x64 with Aegir and I ran into an error I've never had before:

perl: warning: Setting locale failed.                                                                
perl: warning: Please check that your locale settings:                                               
        LANGUAGE = (unset),                                                                          
        LC_ALL = (unset),                                                                            
        LANG = "en_US.UTF-8"                                                                         
    are supported and installed on your system.                                                      
perl: warning: Falling back to the standard locale ("C").                                            
locale: Cannot set LC_CTYPE to default locale: No such file or directory                             
locale: Cannot set LC_MESSAGES to default locale: No such file or directory                          
locale: Cannot set LC_ALL to default locale: No such file or directory

Did a quick google and found that I should run this:

sudo locale-gen en_US.UTF-8

Then run this:

dpkg-reconfigure locales