puppetlabs/puppet · error · SerializationError

Unable to serialize a %{obj}

Error message

Unable to serialize a %{obj}

What it means

Error "Unable to serialize a %{obj}" thrown in puppetlabs/puppet.

Source

Thrown at lib/puppet/pops/serialization/json.rb:205

        else
          @io << ':'
        end
        nesting[1] = cnt - 1
      else
        @io << ','
      end
    end
    private :write_delim

    def write_scalar(obj)
      ext = @type_registry[obj.class]
      if ext.nil?
        case obj
        when Numeric, String, true, false, nil
          @io << Puppet::Util::Json.dump(obj)
          write_delim
        else
          raise SerializationError, _("Unable to serialize a %{obj}") % { obj: obj.class.name }
        end
      else
        write_extension(ext, obj)
      end
    end
    private :write_scalar

    def write_extension(ext, obj)
      @io << '[' << extension_indicator(ext).to_json << ','
      @nested << nil
      write_extension_payload(ext, obj)
      @nested.pop
      if obj.is_a?(Extension::SequenceStart) && obj.sequence_size > 0
        @nested << [false, obj.sequence_size]
      else
        if @io.is_a?(String)
          @io.chop!
        else

View on GitHub (pinned to e227c27540)

When it happens

Trigger: Thrown at lib/puppet/pops/serialization/json.rb:205 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/7e5bba6e3dca1d92. Report an issue: GitHub.