# File lib/chef/environment.rb, line 215
    def update_cookbook_constraint_from_param(index, cookbook_constraint_spec)
      valid = true
      md = cookbook_constraint_spec.match(COMBINED_COOKBOOK_CONSTRAINT)
      if md.nil? || md[2].nil?
        valid = false
        add_cookbook_constraint_error(index, cookbook_constraint_spec)
      elsif self.class.validate_cookbook_version(md[2])
        cookbook_versions[md[1]] = md[2]
      else
        valid = false
        add_cookbook_constraint_error(index, cookbook_constraint_spec)
      end
      valid
    end