Fedora and Python 2

I'll vouch for Perl 5's Unicode support being painful. Even in code where you start off with control over the encodings, you still have to know: what “use utf8” does, when to use “use feature 'unicode_strings'”, that {de,en}code_utf8 are a trap to avoid, the difference between “:encoding(utf-8)” and “:encoding(utf8)” (the latter is another trap!) and things like which DBI plugins use UTF-8 by default and which will mangle data by default (and the switch to enable unicode is usually in a different place for each one).

Those are all things I encountered just in a single project. To be fair it was one where I ended up needing to write custom Encode::* modules, so maybe not representative… but it's still a lot of pain for the sake of not breaking code written pre-Y2K.