Last week I tried to port an old Rails application form Ruby 1.8 to the latest 1.9. My development environment - a Mac OS X Snow Leopard machine - was running fine but the server just didn't want to show the French version of the site. Each time I tried to switch the English locale to the French one it died with the following error:Encoding::CompatibilityError: incompatible character encodings: UTF-8 and ISO-8859-1
It took me a while to find out what went wrong: the server wasn't configured for UTF-8.
Finding the current locale
You can get the current locale on an Ubuntu box with the locale command:LANG=
Installing missing locales
Now, assume the Ruby 1.9 application needs the UTF-8 locale. First check if the needed locale is installed on the system with the locale -a command (shows a list with all available locales). If no UTF-8 locale is installed you can generate one with:$ locale-gen en_US.UTF-8
To change the locale used by your system, modify the file /etc/default/locale to contain, for example:LANG="en_US.UTF-8"
Reboot the system and there you go... Ruby 1.9 should now be smart enough to use UTF-8 strings by default.
Thanks @jbpros for pointing me in the right direction!