class Gem::Specification

def conflicts
  conflicts = {}
  self.runtime_dependencies.each { |dep|
    spec = Gem.loaded_specs[dep.name]
    if spec and not spec.satisfies_requirement? dep
      (conflicts[spec] ||= []) << dep
    end
  }
  env_req = Gem.env_requirement(name)
  (conflicts[self] ||= []) << env_req unless env_req.satisfied_by? version
  conflicts
end