Are you getting a TextMate error like this after upgrading your Mac to Mavericks

/Applications/TextMate.app/Contents/SharedSupport/Support/lib/ui.rb:129: warning: assigned but unused variable - pid
/Applications/TextMate.app/Contents/SharedSupport/Support/lib/progress.rb:57: warning: shadowing outer local variable - params
/Applications/TextMate.app/Contents/SharedSupport/Support/lib/progress.rb:55: warning: assigned but unused variable - ui_process
/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require': /Applications/TextMate.app/Contents/SharedSupport/Support/lib/shelltokenize.rb:74: invalid multibyte escape: /[^\w_\-\+=\/\x7F-\xFF]/ (SyntaxError)
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
from /Applications/TextMate.app/Contents/SharedSupport/Bundles/Subversion.tmbundle/Support/svn_diff.rb:7:in `<top (required)>'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
from -:3:in `<main>'

To fix. Simply downgrade the version of Ruby from 2.0 to 1.8. Both versions are installed. So it is as simple as changing a symbolic link.

Open Terminal which can be found in /Applications/Utilities then run the following commands:

cd /System/Library/Frameworks/Ruby.framework/Versions
sudo rm Current
sudo ln -s 1.8 Current