Upgrade Guide

This document describes breaking changes and how to upgrade. For a complete list of changes including minor and patch releases, please refer to the changelog.

Unreleased

3.3.0

Testing previous versions of the mqt-qmap package built via uv sync or simple (uv) pip install . generally failed due to binary incompatibility of the mqt-core compiled extension packages and the mqt-qmap one. This required building mqt-core from source and without build isolation to get a working local setup. By using the latest pybind11 release (v3), the binary compatibility between extension modules compiled under different circumstances (such as different compilers) has been greatly increased. As such, it is no longer necessary to build mqt-core (and mqt-qcec for testing) from source and without build isolation when locally working on mqt-qmap. A simple uv sync is enough to successfully run pytest.

All Python enums (e.g., sc.Method) are now exposed via pybind11’s new py::native_enum, which makes them compatible with Python’s enum.Enum class (PEP 435). As a result, the enums can no longer be initialized using a string. Instead of Method("exact") or "exact", use Method.exact.

This release restructures the neutral atom compiler which has consequences for its configuration and the reporting of statistics. The placement and routing stages have been merged into a single layout synthesis stage. There is a new PlaceAndRouteSynthesizer that combines the previously separate placement and routing stages. Consequently, the configuration for the placement and routing stages must now be wrapped in a configuration for the layout synthesis stage when using the C++ API. The Python API did not change in this regard. Furthermore, when reporting the statistics of the neutral atom compiler, the statistics for placement and routing are now reported as part of the layout synthesis statistics. The latter affects both the C++ and Python APIs.

Finally, the minimum required C++ version has been raised from C++17 to C++20. The default compilers of our test systems support all relevant features of the standard.

3.2.0

With this release, the Python package has been restructured. In particular, the mqt.qmap.pyqmap module has been discontinued. Classes and functions can now be imported from the more descriptive mqt.qmap.clifford_synthesis, mqt.qmap.hybrid_mapper, mqt.qmap.na, and mqt.qmap.sc modules. The superconducting module’s compile() function has been moved to mqt.qmap.plugins.qiskit.sc. The entrypoints synthesize_clifford() and optimize_clifford() of the Clifford synthesis module have been moved to mqt.qmap.plugins.qiskit.clifford_synthesis.

3.1.0

This minor release initiates the efforts to re-structure the Python bindings and make them more modular. Even tough this is not a breaking change, it is worth mentioning to developers of MQT QMAP that all Python code (except tests) has been moved to the top-level python directory. Furthermore, the C++ code for the Python bindings has been moved to the top-level bindings directory.

3.0.0

This major release introduces several breaking changes, including the removal of deprecated features. The following paragraphs describe the most important changes and how to adapt your code accordingly. We intend to provide a more comprehensive migration guide for future releases.

The major change in this major release is the move to the MQT Core Python package. This move allows us to make qiskit a fully optional dependency and entirely rely on the MQT Core IR for representing circuits. Additionally, the mqt-core Python package now ships all its C++ libraries as shared libraries so that these need not be fetched or built as part of the build process. This was tricky to achieve cross-platform, and you can find some more backstory in the corresponding PR. We expect this integration to mature over the next few releases. If you encounter any issues, please let us know.

Support for BackendV1 Qiskit backends has been removed in accordance with Qiskit’s 2.0 release dropping support for these backends. If you still require support for these backends, please use the last version of MQT QMAP that supports them, which is 2.8.0. However, we strongly recommend that you upgrade to Qiskit 2.0 or higher and use the new BackendV2 interface.

Teleportation support for the heuristic mapping has been removed. If you still require this feature, please use the last version of MQT QMAP that supports it, which is 2.8.0.

MQT Core itself dropped support for several parsers in v3.0.0, including the .real, .qc, .tfc, and GRCS parsers. The .real parser lives on as part of the MQT SyReC project. All others have been removed without replacement. Consequently, these input formats are no longer supported in MQT QMAP.

MQT QMAP has moved to the munich-quantum-toolkit GitHub organization under https://github.com/munich-quantum-toolkit/qmap. While most links should be automatically redirected, please update any links in your code to point to the new location. All links in the documentation have been updated accordingly.

MQT QMAP now requires CMake 3.24 or higher. Most modern operating systems should have this version available in their package manager. Alternatively, CMake can be conveniently installed from PyPI using the cmake package.