ruby regex and grouping

I've got following text 'some-text-here' and try to get the 'text' word from it using groups.

If I use that expression /some-(\w+)-here/ all works fine, but if I try to apply grouping to it /some-(?<group_name>\w+)-here/ it's raise an error Undefined (?...) sequence.

What's I doing wrong?

(Ruby 1.9.2)

Upd: shame on me. It's all from m开发者_高级运维y innatention. Yes, I've use RVM and my ruby version turned on 1.9.2. But I've tested that expression at http://rubular.com/ where it is written at the footer Rubular runs on Ruby 1.8.7. Ruby 1.8.7 and Ruby 1.9.2 have a different regular expression engine. So my expression works on 1.9.2, but does not on 1.8.7

For me that looks like you are looking at the wrong Ruby. Do you maybe have RVM installed?

1.9.2

>> RUBY_VERSION 
=> "1.9.2"
>> s='some-text-here' 
=> "some-text-here"
>> /some-(?<group_name>\w+)-here/ =~ s 
=> 0
>> group_name #=> "text"

1.8.7

>> RUBY_VERSION
=> "1.8.7"
>> s='some-text-here'
=> "some-text-here"
>> /some-(?<group_name>\w+)-here/ =~ s
SyntaxError: compile error
(irb):2: undefined (?...) sequence: /some-(?<group_name>\w+)-here/
    from (irb):2

These are my results with 1.9.2-p290:

irb(main):004:0> "some-text-here".match(/some-(?<test>\w+)-here/)
=> #<MatchData "some-text-here" test:"text">
irb(main):005:0> RUBY_VERSION
=> "1.9.2"