oracle/graal · error · NullPointerException

stackTrace[${i}]

Error message

stackTrace[${i}]

What it means

Error "stackTrace[${i}]" thrown in oracle/graal.

Source

Thrown at espresso/src/com.oracle.truffle.espresso.polyglot/src/com/oracle/truffle/espresso/polyglot/ForeignException.java:131

            if (Polyglot.isForeignObject(cause)) {
                return Polyglot.cast(ForeignException.class, cause);
            } else {
                return (Throwable) cause;
            }
        }
        return null;
    }

    /**
     * Unsupported, {@link ForeignException} instances are by definition foreign and thus
     * stacktraces should not be controllable by the guest.
     */
    @Override
    public void setStackTrace(StackTraceElement[] stackTrace) {
        // Validate arguments to fulfill contract.
        for (int i = 0; i < stackTrace.length; i++) {
            if (stackTrace[i] == null) {
                throw new NullPointerException("stackTrace[" + i + "]");
            }
        }
    }

    @SuppressWarnings("sync-override")
    @Override
    public Throwable fillInStackTrace() {
        return this;
    }

    @SuppressWarnings("sync-override")
    @Override
    public Throwable initCause(Throwable cause) {
        throw new UnsupportedOperationException();
    }
}

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Fix the condition reported by the error: stackTrace[${i}]
2. Check the throwing call site and ensure its documented preconditions (argument values, types, environment, or configuration) are satisfied before the call.

Example fix

Validate inputs and environment so that the failing condition does not occur: stackTrace[${i}]

When it happens

Trigger: Thrown at espresso/src/com.oracle.truffle.espresso.polyglot/src/com/oracle/truffle/espresso/polyglot/ForeignException.java:131 when the library encounters an invalid state.

Common situations: Occurs when a caller violates the contract guarded by this check: stackTrace[${i}]

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/d2f786960690a24e. Report an issue: GitHub.