apple/pkl · error · VmException

cannotFindMethodInScope

cannotFindMethodInScope

Error message

Cannot find method `{0}`.

What it means

Thrown when a `super.method(...)` invocation cannot locate the named method on any superclass of the enclosing class. After walking past VmFunction owners to the enclosing prototype, `findSupermethod` queries `superclass.getMethod(...)`; if the lookup returns null, Pkl reports that the method cannot be found in scope, anchored at the enclosing definition's parent. This is essentially a super-call to a method that does not exist in the inheritance chain.

Source

Thrown at pkl-core/src/main/java/org/pkl/core/ast/expression/member/InvokeSuperMethodNode.java:82

    assert owner.isPrototype();

    var superclass = owner.getVmClass().getSuperclass();
    assert superclass != null;

    // note the use of getMethod() rather than getDeclaredMethod()
    var supermethod = superclass.getMethod(methodName);
    if (supermethod != null) {
      if (needsConst && !supermethod.isConst()) {
        CompilerDirectives.transferToInterpreter();
        throw exceptionBuilder().evalError("methodMustBeConst", methodName.toString()).build();
      }
      return supermethod;
    }

    CompilerDirectives.transferToInterpreter();
    var parent = owner.getParent();
    assert parent != null;
    throw exceptionBuilder()
        .cannotFindMethod(parent, methodName, argumentNodes.length, false)
        .build();
  }
}

View on GitHub (pinned to f3efcbfc9b)

Solutions

1. Check the superclass chain (via `getClass().getSuperclass()` semantics) and confirm a method with that exact name and arity exists; fix the call site name or add the missing method to the superclass.
2. If the method exists only on the current class, call it directly instead of via `super`.
3. If it is a property, not a method, read it without call parentheses or override the intended method.
4. If a parent-class rename caused it, update all `super.oldName()` calls to the new name.

Example fix

// before
open class Base {
  function describe(): String = "base"
}
class Child extends Base {
  function describe(): String = super.toString2() // error: no such method on Base
}

// after
open class Base {
  function describe(): String = "base"
}
class Child extends Base {
  function describe(): String = super.describe() + " child"
}

// Pkl: check the method exists on the superclass chain before a super call
function hasSuperMethod(cls: Class, name: String): Boolean =
  cls.getSuperclass()?.getMethod(name) != null

When it happens

Trigger: Occurs when `super.foo(...)` is written in a class whose superclass chain contains no method named `foo` (the method was never declared, is declared only in the subclass itself, or is a property rather than a method). Also fires when the method name is misspelled or renamed in the parent after a refactor.

Common situations: Renaming or removing a method in a base class while subclasses still call it via `super`; copy-pasting a subclass template that references a super method the parent never had; confusing properties with methods (calling `super.someProp()` when `someProp` is a property); targeting the wrong parent class after changing `extends`.

Related errors

• cannotExtendExternalClass
• noImplementationForAbstractMethod
• noImplementationForAbstractMethods
• invalidSupertype
• methodMustBeConst

AI-assisted analysis of apple/pkl@f3efcbfc9b (2026-09-08). Data as JSON: /api/errors/77c7b4ede2ae27d5. Report an issue: GitHub.