Remove deprecated BIPMapping pass (#10526)

* Remove deprecated BIPMapping pass

This commit removes the deprecated BIPMapping pass. It was deprecated in
qiskit-terra 0.24.0 and the minimum deprecation period has elapsed for
the Qiskit 0.45.0 release. This pass has been moved to an external
plugin that can be installed separately and integrated into the
transpiler more cleanly than a single pass and also separates the
optional dependency on the proprietary CPLEX into a separate package.

* Apply suggestions from code review

Co-authored-by: Kevin Hartman <kevin@hart.mn>

* Remove additional uses of BIPMapping

There were still two locations where the BIPMapping pass was being used.
First the dedicated unit tests, and then also import redirects for the
docs and easier access. This commit removes these locations so nothing
left is using the BIPMapping pass.

* Update optionals documentation

* Update install commands

---------

Co-authored-by: Kevin Hartman <kevin@hart.mn>

qiskit/transpiler/passes/__init__.py

@@ -45,7 +45,6 @@
    LookaheadSwap
    StochasticSwap
    SabreSwap
-   BIPMapping
    Commuting2qGateRouter
 
 Basis Change
@@ -199,7 +198,6 @@
 from .routing import LookaheadSwap
 from .routing import StochasticSwap
 from .routing import SabreSwap
-from .routing import BIPMapping
 from .routing import Commuting2qGateRouter
 
 # basis change

qiskit/transpiler/passes/routing/__init__.py

@@ -17,6 +17,5 @@
 from .lookahead_swap import LookaheadSwap
 from .stochastic_swap import StochasticSwap
 from .sabre_swap import SabreSwap
-from .bip_mapping import BIPMapping
 from .commuting_2q_gate_routing.commuting_2q_gate_router import Commuting2qGateRouter
 from .commuting_2q_gate_routing.swap_strategy import SwapStrategy

qiskit/utils/optionals.py

@@ -58,7 +58,8 @@
     * - .. py:data:: HAS_CPLEX
       - The `IBM CPLEX Optimizer <https://www.ibm.com/analytics/cplex-optimizer>`__ is a
         high-performance mathematical programming solver for linear, mixed-integer and quadratic
-        programming.  It is required by the :class:`.BIPMapping` transpiler pass.
+        programming. This is no longer by Qiskit, but it weas historically and the optional
+        remains for backwards compatibility.
 
     * - .. py:data:: HAS_CVXPY
       - `CVXPY <https://www.cvxpy.org/>`__ is a Python package for solving convex optimization
@@ -68,7 +69,8 @@
     * - .. py:data:: HAS_DOCPLEX
       - `IBM Decision Optimization CPLEX Modelling
         <http://ibmdecisionoptimization.github.io/docplex-doc/>`__ is a library for prescriptive
-        analysis.  Like CPLEX, it is required for the :class:`.BIPMapping` transpiler pass.
+        analysis.  Like CPLEX, this is no longer by Qiskit, but it weas historically and the
+        optional remains for backwards compatibility.
 
     * - .. py:data:: HAS_FIXTURES
       - The test suite has additional features that are available if the optional `fixtures
@@ -246,13 +248,13 @@
 
 HAS_CPLEX = _LazyImportTester(
     "cplex",
-    install="pip install 'qiskit-terra[bip-mapper]'",
+    install="pip install cplex",
     msg="This may not be possible for all Python versions and OSes",
 )
 HAS_CVXPY = _LazyImportTester("cvxpy", install="pip install cvxpy")
 HAS_DOCPLEX = _LazyImportTester(
     {"docplex": (), "docplex.mp.model": ("Model",)},
-    install="pip install 'qiskit-terra[bip-mapper]'",
+    install="pip install docplex",
     msg="This may not be possible for all Python versions and OSes",
 )
 HAS_FIXTURES = _LazyImportTester("fixtures", install="pip install fixtures")

releasenotes/notes/remove-deprecated-bip-mapper-e1206c8f905502dd.yaml

@@ -0,0 +1,15 @@
+---
+upgrade:
+  - |
+    The deprecated transpiler routing pass, ``BIPMapping`` has been removed.
+    It was marked as deprecated in the Qiskit 0.43.0 release. It has been
+    replaced by an external plugin package: ``qiskit-bip-mapper``. Details for
+    this new package can be found at the package's github repository:
+
+        https://github.com/qiskit-community/qiskit-bip-mapper
+
+    The pass was made into a separate plugin package for two reasons, first
+    the dependency on CPLEX makes it harder to use and secondly the plugin
+    package more cleanly integrates with :func:`~.transpile`. The optional
+    extra ``bip-mapper`` to install the ``cplex`` and ``docplex`` to support
+    this pass has been removed as nothing in Qiskit optionally requires it anymore.