What causes "Error invoking %s#getAssociatedTypeConstructor" in bazelbuild/bazel?

Inspect the chained cause to find the real failure inside the method body and fix it.

bazelbuild/bazel · error · IllegalArgumentException

Error invoking #getAssociatedTypeConstructor

Error message

Error invoking %s#getAssociatedTypeConstructor

What it means

The signature check passed, but invoking getAssociatedTypeConstructor via reflection failed: IllegalAccessException (access blocked despite being public, e.g. module boundaries), InvocationTargetException (the method body threw), or the body threw a RuntimeException directly (e.g. NPE while initializing a static type constructor). The original exception is chained as the cause.

Solutions

Inspect the chained cause to find the real failure inside the method body and fix it.
Make the static accessor defensive: build the TypeConstructor lazily or from fully-initialized constants.
On JDK 9+, ensure the package is exported/opened to the reflecting module.
Avoid circular static initialization between the class and its type constructor.

Example fix

// before
public static TypeConstructor getAssociatedTypeConstructor() {
  return Registry.lookup("mytype"); // throws if registry not yet populated
}

// after
private static final TypeConstructor CTOR = TypeConstructor.of("mytype");
public static TypeConstructor getAssociatedTypeConstructor() { return CTOR; }

Defensive patterns

Strategy: try-catch

Try / catch

try {
  TypeConstructor tc = CallUtils.getAssociatedTypeConstructor(clazz);
} catch (IllegalArgumentException e) {
  Throwable root = e.getCause() != null ? e.getCause() : e;
  throw new IllegalStateException("type constructor init failed for " + clazz, root);
}

Prevention

Initialize type constructors from constants, not registries populated later.
Avoid circular static initialization between a class and its type constructor.
On JDK 9+, open/export the declaring package to reflective callers.

When it happens

Trigger: The static method body throws (null type registry, circular static init, missing dependency); JPMS denies access to the declaring class; static initializer order causes the constructor to depend on not-yet-initialized state.

Common situations: Type constructor built from a registry that is only populated later; module-info or --add-exports missing in JDK 9+ environments; exception thrown during class initialization surfacing as ExceptionInInitializerError wrapped here.

Related errors

AI-assisted analysis of bazelbuild/bazel@e6e199d060 (2026-08-14). Data as JSON: /api/errors/c2c14e2f4c373195. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/net/starlark/java/eval/CallUtils.java:481

      return null;
    }

    // Signature check.
    if (!Modifier.isPublic(found.getModifiers())
        || !Modifier.isStatic(found.getModifiers())
        || !found.getReturnType().equals(TypeConstructor.class)
        || found.getParameterCount() != 0) {
      throw new IllegalArgumentException(
          String.format(
              "Method %s#getAssociatedTypeConstructor has an invalid signature; "
                  + "expected 'public static TypeConstructor getAssociatedTypeConstructor()'",
              clazz.getName()));
    }

    try {
      return (TypeConstructor) found.invoke(null);
    } catch (IllegalAccessException | InvocationTargetException | RuntimeException e) {
      throw new IllegalArgumentException(
          String.format("Error invoking %s#getAssociatedTypeConstructor", clazz.getName()), e);
    }
  }
}

View on GitHub (pinned to e6e199d060)