I'm running Ruby 1.9.1-p378 (RC2) on windows, installed from the
RubyInstaller.org site.
I've installed 'extensions' gem ("gem install -r extensions").

When I run irb and try and "require 'extensions/all" I get the
following error:

C:\Windows\System32>irb
irb(main):001:0> require 'rubygems'
=> false
irb(main):002:0> require 'extensions/all'
NameError: uninitialized constant VERSION
      [snip]

Some code in the extensions/_base.rb is checking VERSION to determine
if running on a new enough version of ruby. This constant isn't
defined (NB: RUBY_VERSION is defined).

When I set VERSION = RUBY_VERSION before require'ing 'extensions/all'
I get this error instead:

RuntimeError: Ruby/Extensions: internal error: was supposed to
implement Array#select!, but it didn't!
        from C:/Ruby19/lib/ruby/gems/1.9.1/gems/extensions-0.6.0/lib/
extensions/_base.rb:113:in `implement'

Does anyone recognise this problem?