users_manage LWRP requires you to include_recipe "users::sysadmins", which may not be acceptable if say your system(s) already use GID 2300 for another group or you do not want to create the sysadmins group for whatever reason. The fix is as simple as creating an empty recipes/default.rb so you can include_recipe "users" and use the cookbook LWRPs.
From http://tickets.opscode.com/browse/COOK-2021:
users_manage LWRP requires you to include_recipe "users::sysadmins", which may not be acceptable if say your system(s) already use GID 2300 for another group or you do not want to create the sysadmins group for whatever reason. The fix is as simple as creating an empty recipes/default.rb so you can include_recipe "users" and use the cookbook LWRPs.