* Unstable feature `unstable_chain_with_environment` macros have been moved to their own feature instead of incorporating the feature gate into the macros.
1.9.0
* Unstable feature `unstable_chain_with_environment` implementing a Trait for returning chains in a device with an environment of qubits, where an environment are qubits that are not part of the chain but connected to at least one qubit in the chain.