Troubleshooting

A backend is missing. Install its extra, for example pip install "superquantx[qiskit]", or all of them with uv sync --extra all-backends. Then run superquantx list-backends, which runs a Bell circuit on each backend and prints the error for any that fail.

braket fails to start. Use the local simulator explicitly: sqx.get_backend("braket", device="local:braket_sv"). Real Braket devices need AWS credentials.

ocean raises an error for a circuit. D-Wave Ocean is an annealer. It solves QUBO/Ising problems and does not run gate-model circuits. Hardware access needs a D-Wave Leap token.

An algorithm result has error set. BaseQuantumAlgorithm.optimize records exceptions on the returned QuantumResult.error instead of raising. Check it before using the result.

Results differ in bit order between backends. Use backend.counts_big_endian(result["counts"]) and backend.statevector_big_endian(circuit), which normalise every backend to big-endian (qubit 0 is the leftmost bit).

Tests fail with "async def functions are not natively supported". Install the dev extra, which includes pytest-asyncio: uv sync --extra dev.