qiskit/releasenotes/notes/0.24/remove-faulty-qubits-suppor...

17 lines
978 B
YAML

---
upgrade:
- |
When running the :func:`~.transpile` function with a :class:`~.BackendV1`
based backend or a :class:`~.BackendProperties` via the ``backend_properties``
keyword argument that has any qubits or gates flagged as faulty the function
will no longer try to automatically remap the qubits based on this information.
The method by which :func:`~.transpile` attempted to do this remapping was
fundamentally flawed and in most cases of such a backend it would result
an internal error being raised. In practice very few backends ever set the
fields in :class:`~.BackendProperties` to flag a qubit or gate as faulty.
If you were somehow successfully relying on :func:`~.transpile to do this
re-mapping for you will now need to manually do that and pass a
mapped input to the ``coupling_map`` and ``backend_properties`` arguments
which has filtered out the faulty qubits and gates and then manually re-map
the output.