What causes "The function call setEnvironmentVar requires 2 arguments." in pentaho/pentaho-kettle?

Call setEnvironmentVar(name, value) with exactly two String arguments.

pentaho/pentaho-kettle · error · RuntimeException

The function call setEnvironmentVar requires 2 arguments.

Error message

The function call setEnvironmentVar requires 2 arguments.

What it means

Arity guard for setEnvironmentVar in the script step: the function was invoked without exactly two arguments (name, value). Any count other than 2 falls into the else-branch and throws, because System.setProperty needs exactly one key and one value.

Solutions

Call setEnvironmentVar(name, value) with exactly two String arguments.
Split multiple variables into separate calls.
Coerce values with String(...) to avoid the companion e.toString() error.

Example fix

// before
setEnvironmentVar('MY_VAR'); // throws
// after
setEnvironmentVar('MY_VAR', 'myValue');

Defensive patterns

Strategy: validation

Validate before calling

function safeSetEnv(name, value) {
  if (arguments.length !== 2) throw new Error('setEnvironmentVar requires exactly 2 arguments');
  setEnvironmentVar(name, value);
}

Try / catch

try {
  setEnvironmentVar(name, value);
} catch (e) {
  if (String(e.message).indexOf('requires 2 arguments') >= 0) {
    // fix the call site arity
  }
}

Prevention

Always pass exactly two arguments: name and value.
Set each variable in its own call.
Fix arity errors at the call site rather than catching and swallowing.

When it happens

Trigger: Calling setEnvironmentVar(name) with one argument, or with three or more arguments, in a JavaScript transformation step.

Common situations: Forgetting the value argument, attempting to set several variables in one call, refactoring typos.

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 pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/e7069e2f8820a9ad. Report an issue: GitHub.

Appendix: source

Thrown at engine/src/main/java/org/pentaho/di/trans/steps/script/ScriptAddedFunctions.java:1555

    return "";
  }

  // Setting EnvironmentVar
  public static void setEnvironmentVar( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {
    String sArg1 = "";
    String sArg2 = "";
    if ( ArgList.length == 2 ) {
      try {
        sArg1 = (String) ArgList[0];
        sArg2 = (String) ArgList[1];
        System.setProperty( sArg1, sArg2 );
      } catch ( Exception e ) {
        throw new RuntimeException( e.toString() );
      }
    } else {
      throw new RuntimeException( "The function call setEnvironmentVar requires 2 arguments." );
    }
  }

  // Returning EnvironmentVar
  public static String getEnvironmentVar( ScriptEngine actualContext, Bindings actualObject, Object[] ArgList,
    Object FunctionContext ) {
    String sRC = "";
    if ( ArgList.length == 1 ) {
      try {
        String sArg1 = (String) ArgList[0];
        sRC = System.getProperty( sArg1, "" );
      } catch ( Exception e ) {
        sRC = "";
      }
    } else {
      throw new RuntimeException( "The function call getEnvironmentVar requires 1 argument." );
    }
    return sRC;

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