{"record":{"id":"c43bec1794264e54","repo":"fluent/fluentd","slug":"unknown-fluentd-configuration-syntax-syntax","errorCode":null,"errorMessage":"Unknown Fluentd configuration syntax: '#{syntax}'","messagePattern":"Unknown Fluentd configuration syntax: '#(.+?)'","errorType":"exception","errorClass":"ArgumentError","httpStatus":null,"severity":"error","filePath":"lib/fluent/config.rb","lineNumber":63,"sourceCode":"        if additional_config\n          c = additional_config.gsub(\"\\\\n\", \"\\n\")\n          s += \"\\n#{c}\"\n        end\n        s\n      end\n\n      Fluent::Config.parse(config_data, config_fname, config_basedir, use_v1_config, on_file_parsed: on_file_parsed)\n    end\n\n    def self.parse(str, fname, basepath = Dir.pwd, v1_config = nil, syntax: :v1, on_file_parsed: nil)\n      parser = if fname =~ /\\.rb$/ || syntax == :ruby\n                 :ruby\n               elsif v1_config.nil?\n                 case syntax\n                 when :v1 then :v1\n                 when :v0 then :v0\n                 else\n                   raise ArgumentError, \"Unknown Fluentd configuration syntax: '#{syntax}'\"\n                 end\n               elsif v1_config then :v1\n               else :v0\n               end\n      case parser\n      when :v1\n        require 'fluent/config/v1_parser'\n        V1Parser.parse(str, fname, basepath, Kernel.binding, on_file_parsed: on_file_parsed)\n      when :v0\n        # TODO: show deprecated message in v1\n        require 'fluent/config/parser'\n        Parser.parse(str, fname, basepath)\n      when :ruby\n        require 'fluent/config/dsl'\n        $log.warn(\"Ruby DSL configuration format is deprecated. Please use original configuration format. https://docs.fluentd.org/configuration/config-file\") if $log\n        Config::DSL::Parser.parse(str, File.join(basepath, fname))\n      else\n        raise \"[BUG] unknown configuration parser specification:'#{parser}'\"","sourceCodeStart":45,"sourceCodeEnd":81,"githubUrl":"https://github.com/fluent/fluentd/blob/dd45c6e18dc7be33b5e5a0f0767bf46307ff5626/lib/fluent/config.rb#L45-L81","documentation":"Error \"Unknown Fluentd configuration syntax: '#{syntax}'\" thrown in fluent/fluentd.","triggerScenarios":"Thrown at lib/fluent/config.rb:63 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"dd45c6e18dc7be33b5e5a0f0767bf46307ff5626","analyzedAt":"2026-08-21T16:22:07.332Z","schemaVersion":2},"datasetVersion":"2026-08-21T18:17:14.833Z"}