stanfordnlp/CoreNLP · error · IllegalArgumentException

Must specify a treebank to train from with -trainTreebank…

Error message

Must specify a treebank to train from with -trainTreebank or a parser to load with -serializedPath

What it means

ShiftReduceParser.main is the command-line entry point for training or loading a shift-reduce parser. It requires either a training treebank path (-trainTreebank) to train a new model, or a serialized parser path (-serializedPath) to load an existing one. If neither is given it cannot do anything meaningful and throws IllegalArgumentException.

Solutions

Pass -trainTreebank <path> to train a new parser from treebank data
Or pass -serializedPath <model.ser.gz> to load an existing parser
Verify flag spelling and that your launcher script actually forwards the arguments

Example fix

// before
java edu.stanford.nlp.parser.shiftreduce.ShiftReduceParser -trainingMethod BEAM

// after
java edu.stanford.nlp.parser.shiftreduce.ShiftReduceParser -serializedPath model.ser.gz -testTreebank tests/treebank

Defensive patterns

Strategy: validation

Validate before calling

if (args == null || (Arrays.stream(args).noneMatch(a -> a.startsWith("-trainTreebank"))
    && Arrays.stream(args).noneMatch(a -> a.startsWith("-serializedPath")))) {
  throw new IllegalArgumentException("Usage: ShiftReduceParser -trainTreebank <path> | -serializedPath <model>");
}

Try / catch

try {
  ShiftReduceParser.main(args);
} catch (IllegalArgumentException e) {
  log.severe("Usage: must pass -trainTreebank or -serializedPath");
  System.exit(2);
}

Prevention

Wrap the CLI in a script that validates required flags
Watch for flag case-sensitivity typos
Document both invocation modes (train vs load)

When it happens

Trigger: Running java edu.stanford.nlp.parser.shiftreduce.ShiftReduceParser (or Main) with neither -trainTreebank nor -serializedPath on the command line.

Common situations: Mis-typed CLI flags (e.g. -trainTreeBank with wrong case), an options file whose values weren't passed through, or a script that dropped the model path argument.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/db0962c7033532bb. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/parser/shiftreduce/ShiftReduceParser.java:642

        serializedPath = args[argIndex + 1];
        argIndex += 2;
      } else if (args[argIndex].equalsIgnoreCase("-tlpp")) {
        tlppClass = args[argIndex + 1];
        argIndex += 2;
      } else if (args[argIndex].equalsIgnoreCase("-continueTraining")) {
        continueTraining = args[argIndex + 1];
        argIndex += 2;
      } else {
        remainingArgs.add(args[argIndex]);
        ++argIndex;
      }
    }

    String[] newArgs = new String[remainingArgs.size()];
    newArgs = remainingArgs.toArray(newArgs);

    if (trainTreebankPath == null && serializedPath == null) {
      throw new IllegalArgumentException("Must specify a treebank to train from with -trainTreebank or a parser to load with -serializedPath");
    }

    ShiftReduceParser parser = null;

    if (trainTreebankPath != null) {
      log.info("Training ShiftReduceParser");
      log.info("Initial arguments:");
      log.info("   " + StringUtils.join(args));
      if (continueTraining != null) {
        parser = ShiftReduceParser.loadModel(continueTraining, ArrayUtils.concatenate(BASIC_TRAINING_OPTIONS, newArgs));
      } else {
        ShiftReduceOptions op = buildTrainingOptions(tlppClass, newArgs);
        parser = new ShiftReduceParser(op);
      }
      Timing trainingTimer = new Timing();
      parser.train(trainTreebankPath, devTreebankPath, serializedPath);
      trainingTimer.done("Overall training process");
      parser.saveModel(serializedPath);

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