apple/pkl · error

fatal: failed to tear down graal isolate.

Error message

fatal: failed to tear down graal isolate.

What it means

Fatal check in pkl_close: graal_tear_down_isolate returned non-zero, meaning the GraalVM isolate could not be shut down cleanly; the process aborts because a half-torn-down isolate is unrecoverable. Typically indicates lingering threads attached to, or work still running in, the isolate.

Solutions

1. Ensure all evaluation work and the dispatch worker are stopped before pkl_close (pkl_internal_server_stop already does this — check for extra attached threads).
2. Call pkl_close exactly once, from the same thread that ran pkl_init.

When it happens

Trigger: Thrown at libpkl/src/main/c/pkl.c:239 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of apple/pkl@f3efcbfc9b (2026-09-08). Data as JSON: /api/errors/8303be21ca9c2192. Report an issue: GitHub.

Appendix: source

Thrown at libpkl/src/main/c/pkl.c:239

		}
		return -1;
	}

	graal_isolatethread_t *thread = graal_get_current_thread(pexec->isolate);
	if (thread != pexec->isolateThread) {
		if (error != NULL) {
			error->message = "called into pkl_close from different thread";
		}
		return PKL_ERR_THREAD;
	}

	// pkl_internal_server_stop unblocks queue_thread's pending/next poll call, so the join
	// below is guaranteed to return; only then is it safe to tear down the isolate.
	pkl_internal_server_stop(thread);
	pkl_stop_dispatch_worker(pexec);

	if (graal_tear_down_isolate(thread) != 0) {
		fprintf(stderr, "fatal: failed to tear down graal isolate.\n");
		abort();
	}

	free(pexec);
	if (error != NULL) {
		error->message = NULL;
	}
	return 0;
}

const char* pkl_version() {
	return PKL_VERSION;
}

View on GitHub (pinned to f3efcbfc9b)