Prepare Qiskit 2.3.1 (#15803)

Author: jakelishman

Cargo.lock

@@ -3,7 +3,7 @@ members = ["crates/*"]
 resolver = "2"
 
 [workspace.package]
-version = "2.3.0"
+version = "2.3.1"
 edition = "2024"
 rust-version = "1.85"  # Keep in sync with README.md, rust-toolchain.toml, and tools/install_rust_msrv.sh
 license = "Apache-2.0"

Cargo.toml

@@ -20,12 +20,12 @@
 
 #define QISKIT_VERSION_MAJOR 2
 #define QISKIT_VERSION_MINOR 3
-#define QISKIT_VERSION_PATCH 0
+#define QISKIT_VERSION_PATCH 1
 #define QISKIT_RELEASE_LEVEL QISKIT_RELEASE_LEVEL_FINAL
 // For the final release, set the below to 0.
 #define QISKIT_RELEASE_SERIAL 0
 
-#define QISKIT_VERSION "2.3.0"
+#define QISKIT_VERSION "2.3.1"
 
 #define QISKIT_GET_VERSION_HEX(major, minor, patch, level, serial)                                 \
     (((major) & 0xff) << 24 | ((minor) & 0xff) << 16 | ((patch) & 0xff) << 8 |                     \

crates/cext/include/qiskit/version.h

@@ -1 +1 @@
-2.3.0
+2.3.1

qiskit/VERSION.txt

@@ -1,10 +1,6 @@
 ---
 fixes:
   - |
-    Fixed a bug in :meth:`~qiskit.circuit.ParameterExpression.sympify()` where reverse power
-    operations (RPOW) were incorrectly converting to sympy expressions with swapped operands.
-    Previously, expressions like ``a ** (b - 2)`` would incorrectly convert to ``(b - 2)**a``
-    instead of ``a ** (b - 2)``. The fix adds proper handling for reverse operations (RPOW,
-    RDIV, RSUB) to correctly swap operands before applying the operation, matching the Rust
-    implementation behavior.
-
+    Fixed a bug in :meth:`.ParameterExpression.sympify` where asymmetric arithmetic operations (such
+    as `**` or `-`) could have the operands reversed with certain combinations of :class:`.Parameter`,
+    :class:`.ParameterExpression` and numeric values.  See `#15642 <https://github.com/Qiskit/qiskit/pull/15642>`__.

releasenotes/notes/fix-parameter-expression-rpow-sympify-15583.yaml

@@ -2,9 +2,5 @@
 fixes:
   - |
     Fixed a visualization artifact in :func:`~qiskit.visualization.plot_state_qsphere` where
-    symmetric entangled states (e.g., Bell states) were arbitrarily rotated due to floating-point
-    noise. Previously, microscopic noise introduced by the internal eigensolver could cause the
-    visualization to select the wrong basis state as the global phase anchor (Phase 0). A rounding
-    step has been added to filter this noise, ensuring stable and canonical orientation for
-    symmetric states.
-
+    symmetric entangled states (such as Bell states) were arbitrarily rotated due to floating-point
+    noise.

releasenotes/notes/fix-qsphere-anchor-b46ad3451ac89fc3.yaml

@@ -1,5 +1,6 @@
 ---
 fixes:
   - |
-    The rust ``is_control_flow`` method now returns ``false`` on :class:`.ContinueLoopOp` and :class:`.BreakLoopOp` constructs
-    as is expected by the parts of the code that use it. Fixed `#15579 <https://github.com/Qiskit/qiskit/issues/15579>`__.
+    Fixed :class:`.BreakLoopOp` and :class:`.ContinueLoopOp` being falsely considered control-flow
+    operations in certain transpiler passes, which could manifest as an :exc:`AttributeError` being raised.
+    See `#15579 <https://github.com/Qiskit/qiskit/issues/15579>`__.

releasenotes/notes/fix_is_control_flow-7e48e552d41f80b8.yaml

@@ -0,0 +1,3 @@
+---
+prelude: >
+  Qiskit v2.3.1 fixes several bugs identified since the release of Qiskit v2.3.0.