puppetlabs/puppet · error · Puppet::ParseError

conflicts with attribute with the same name

Error message

%{label} conflicts with attribute with the same name

What it means

An Object type may declare both attributes and functions, but they share one member namespace on the generated class. When a function is created whose name equals an already-declared attribute name, Puppet::ParseError is raised stating that the function label conflicts with an attribute of the same name.

Solutions

  1. Rename either the function or the attribute so both names are unique within the type (e.g. size vs size_label)
  2. If the function was meant to replace an inherited attribute's behavior, override the attribute instead of declaring a same-named function

Example fix

# before
type MyApp::T = Object[{
  attributes => { size => Integer },
  functions => { size => Callable[[], String] }
}]

# after
type MyApp::T = Object[{
  attributes => { size => Integer },
  functions => { size_label => Callable[[], String] }
}]
Defensive patterns

Strategy: validation

Validate before calling

# assert function names and attribute names are disjoint
overlap = (func_specs.keys & attr_specs.keys)
raise "function/attribute name conflict: #{overlap.inspect}" unless overlap.empty?

Try / catch

begin
  Puppet::Pops::Types::PObjectType.new(name, init_hash)
rescue Puppet::ParseError => e
  raise unless e.message =~ /conflicts with attribute with the same name/
  raise  # e.message names the function; rename it or the attribute
end

Prevention

When it happens

Trigger: A type definition with functions => { size => Callable[[], String] } while size is also declared (or inherited onto this type's own attribute map) under attributes => { size => Integer }. The check runs during type resolution, before any instance exists.

Common situations: Adding a derived-value function whose name naturally collides with an attribute (size, name, version); renaming members on one side only; inheriting members from a parent and redefining the name as a function in the child.

Related errors

AI-assisted analysis of puppetlabs/puppet@e227c27540 (2026-08-21). Data as JSON: /api/errors/7249217681e6daf1. Report an issue: GitHub.

Appendix: source

Thrown at lib/puppet/pops/types/p_object_type.rb:775

    unless attr_specs.empty?
      @attributes = attr_specs.to_h do |key, attr_spec|
        unless attr_spec.is_a?(Hash)
          attr_type = TypeAsserter.assert_instance_of(nil, PTypeType::DEFAULT, attr_spec) { "attribute #{label}[#{key}]" }
          attr_spec = { KEY_TYPE => attr_type }
          attr_spec[KEY_VALUE] = nil if attr_type.is_a?(POptionalType)
        end
        attr = PAttribute.new(key, self, attr_spec)
        [attr.name, attr.assert_override(parent_members)]
      end.freeze
    end

    func_specs = init_hash[KEY_FUNCTIONS]
    unless func_specs.nil? || func_specs.empty?
      @functions = func_specs.to_h do |key, func_spec|
        func_spec = { KEY_TYPE => TypeAsserter.assert_instance_of(nil, TYPE_FUNCTION_TYPE, func_spec) { "function #{label}[#{key}]" } } unless func_spec.is_a?(Hash)
        func = PFunction.new(key, self, func_spec)
        name = func.name
        raise Puppet::ParseError, _("%{label} conflicts with attribute with the same name") % { label: func.label } if @attributes.include?(name)

        [name, func.assert_override(parent_members)]
      end.freeze
    end

    @equality_include_type = init_hash[KEY_EQUALITY_INCLUDE_TYPE]
    @equality_include_type = true if @equality_include_type.nil?

    equality = init_hash[KEY_EQUALITY]
    equality = [equality] if equality.is_a?(String)
    if equality.is_a?(Array)
      unless equality.empty?
        # TRANSLATORS equality_include_type = false should not be translated
        raise Puppet::ParseError, _('equality_include_type = false cannot be combined with non empty equality specification') unless @equality_include_type

        parent_eq_attrs = nil
        equality.each do |attr_name|
          attr = parent_members[attr_name]

View on GitHub (pinned to e227c27540)