apple/pkl · error · VmException

methodNotDefined5

methodNotDefined5

Error message

methodNotDefined5

What it means

ExternalMethod5Node implements five-argument stdlib methods. If dispatch cannot match the receiver and all five argument types to any defined node, the @Fallback throws "methodNotDefined5" with the method name and the class of each of the five arguments. This is the largest-arity variant of Pkl's method-not-defined family.

Source

Thrown at pkl-core/src/main/java/org/pkl/core/stdlib/ExternalMethod5Node.java:49

  protected abstract ExpressionNode getArg2Node();

  protected abstract ExpressionNode getArg3Node();

  protected abstract ExpressionNode getArg4Node();

  protected abstract ExpressionNode getArg5Node();

  @Fallback
  @TruffleBoundary
  protected Object fallback(
      @SuppressWarnings("unused") Object receiver,
      Object arg1,
      Object arg2,
      Object arg3,
      Object arg4,
      Object arg5) {
    throw exceptionBuilder()
        .evalError(
            "methodNotDefined5",
            getQualifiedMemberName(),
            VmUtils.getClass(arg1),
            VmUtils.getClass(arg2),
            VmUtils.getClass(arg3),
            VmUtils.getClass(arg4),
            VmUtils.getClass(arg5))
        .withProgramValue("Argument 1", arg1)
        .withProgramValue("Argument 2", arg2)
        .withProgramValue("Argument 3", arg3)
        .withProgramValue("Argument 4", arg4)
        .withProgramValue("Argument 5", arg5)
        .build();
  }

  public interface Factory {
    ExternalMethod5Node create(

View on GitHub (pinned to f3efcbfc9b)

Solutions

1. Compare every reported argument class to the documented parameter types.
2. Normalize interop data (YAML/JSON) explicitly — convert Numbers/Strings to the expected Pkl types before the call.
3. Refactor the call into named intermediate values so each argument's type is visible and testable.
4. Confirm the overload exists in the Pkl version in use; upgrade or adjust the call accordingly.

Example fix

// before
pairs.map(values, keys, transform, /* filter */ null, /* limit */ "10")
// after
pairs.map(values, keys, transform, null, 10) // Int limit

// Pkl
assert(args.every((a) -> a != null), "no argument may be null here")

function isNonNull(x) = x != null
// combine with per-slot checks: a is Int, b is String, ...

When it happens

Trigger: Calling a five-argument stdlib method where at least one argument's dynamic type matches no overload — e.g. a null from an optional property or a List passed where a Function/predicate is required.

Common situations: Deeply positional calls where an argument is silently omitted or shifted; refactors changing a parameter's type without updating all call sites; interop values (YAML/JSON) arriving as different Pkl types than assumed.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• methodNotDefined1
• methodNotDefined2
• methodNotDefined3
• methodNotDefined4
• Error converting property `%s` in Pkl object of type `%s` to

AI-assisted analysis of apple/pkl@f3efcbfc9b (2026-09-08). Data as JSON: /api/errors/81624414097561bb. Report an issue: GitHub.