# cat grp.pp 
group { "foo": gid => 2000 }

# puppet grp.pp 
err: //Group[foo]/ensure: change from absent to present failed: Could not set present on ensure: undefined method `allowdupe?' for # at /tmp/grp.pp:1
# < after edit > 
# puppet grp.pp 
notice: //Group[foo]/ensure: defined 'ensure' as 'present'
# diff -c /usr/lib/ruby/site_ruby/1.8/puppet/type/group.rb /usr/lib/ruby/site_ruby/1.8/puppet/type/group.rb.old 
*** /usr/lib/ruby/site_ruby/1.8/puppet/type/group.rb    2008-07-08 22:06:43.000000000 -0400
--- /usr/lib/ruby/site_ruby/1.8/puppet/type/group.rb.old        2008-07-07 22:52:21.000000000 -0400
***************
*** 110,116 ****
              isnamevar
          end

!         newparam(:allowdupe, :boolean => true) do
              desc "Whether to allow duplicate GIDs.  This option does not work on
                  FreeBSD (contract to the ``pw`` man page)."

--- 110,116 ----
              isnamevar
          end

!         newparam(:allowdupe) do
              desc "Whether to allow duplicate GIDs.  This option does not work on
                  FreeBSD (contract to the ``pw`` man page)."