puppetlabs/puppet · error · ArgumentError

Function %{class_name}(): Unknown function: '%{function_name

Error message

Function %{class_name}(): Unknown function: '%{function_name}'

What it means

Error "Function %{class_name}(): Unknown function: '%{function_name}'" thrown in puppetlabs/puppet.

Source

Thrown at lib/puppet/pops/functions/function.rb:125

    the_loader = loader
    unless the_loader
      raise ArgumentError, _("Function %{class_name}(): cannot call function '%{function_name}' - no loader specified") %
                           { class_name: self.class.name, function_name: function_name }
    end

    func = the_loader.load(:function, function_name)
    if func
      Puppet::Util::Profiler.profile(function_name, [:functions, function_name]) do
        return func.call(scope, *args, &block)
      end
    end

    # Check if a 3x function is present. Raise a generic error if it's not to allow upper layers to fill in the details
    # about where in a puppet manifest this error originates. (Such information is not available here).
    loader_scope = closure_scope
    func_3x = Puppet::Parser::Functions.function(function_name, loader_scope.environment) if loader_scope.is_a?(Puppet::Parser::Scope)
    unless func_3x
      raise ArgumentError, _("Function %{class_name}(): Unknown function: '%{function_name}'") %
                           { class_name: self.class.name, function_name: function_name }
    end

    # Call via 3x API
    # Arguments must be mapped since functions are unaware of the new and magical creatures in 4x.
    # NOTE: Passing an empty string last converts nil/:undef to empty string
    result = scope.send(func_3x, Puppet::Pops::Evaluator::Runtime3FunctionArgumentConverter.map_args(args, loader_scope, ''), &block)

    # Prevent non r-value functions from leaking their result (they are not written to care about this)
    Puppet::Parser::Functions.rvalue?(function_name) ? result : nil
  end
end

View on GitHub (pinned to e227c27540)

When it happens

Trigger: Thrown at lib/puppet/pops/functions/function.rb:125 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of puppetlabs/puppet@e227c27540 (2026-08-21). Data as JSON: /api/errors/678c0ecc0ed842f1. Report an issue: GitHub.