Add Python 3.15 support

.github/actions/build-wheel/action.yml

@@ -134,7 +134,7 @@ runs:
 
     - name: Build wheel
       if: ${{ inputs.cibw-build == '' }}
-      uses: pypa/cibuildwheel@v3.4.1
+      uses: pypa/cibuildwheel@v4.3.5
       with:
         output-dir: ${{ inputs.output-dir }}
       env:
@@ -143,7 +143,7 @@ runs:
 
     - name: Build selected wheel
       if: ${{ inputs.cibw-build != '' }}
-      uses: pypa/cibuildwheel@v3.4.1
+      uses: pypa/cibuildwheel@v4.3.5
       with:
         output-dir: ${{ inputs.output-dir }}
       env:

.github/workflows/canary.yml

@@ -17,7 +17,7 @@ jobs:
     timeout-minutes: 75
     strategy:
       matrix:
-        python-version: ["3.14"]
+        python-version: ["3.15"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v5

.github/workflows/merge.yml

@@ -37,7 +37,7 @@ jobs:
       - name: Build Basilisk
         uses: ./.github/actions/build
         with:
-          python-version: 3.14
+          python-version: "3.15"
           conan-args: ${{ matrix.conan-args }}
           save-conan-cache: true
 

.github/workflows/nightly-wheels.yml

@@ -96,7 +96,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: 3.14
+          python-version: "3.15"
 
       - name: Download core wheel input
         uses: actions/download-artifact@v6

.github/workflows/publish-wheels.yml

@@ -128,7 +128,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: 3.14
+          python-version: "3.15"
 
       - name: Download core wheel input
         uses: actions/download-artifact@v6
@@ -197,7 +197,7 @@ jobs:
 
       - uses: actions/setup-python@v6
         with:
-          python-version: 3.14
+          python-version: "3.15"
 
       - name: Download sdist
         uses: actions/download-artifact@v6

.github/workflows/pull-request.yml

@@ -62,7 +62,7 @@ jobs:
       # Windows, and macOS.
       - uses: ./.github/actions/build
         with:
-          python-version: 3.14
+          python-version: "3.15"
           conan-args: --opNav True --mujoco True --rustModules True
           save-conan-cache: true
       - name: Verify Corrosion configuration
@@ -125,7 +125,7 @@ jobs:
       - uses: ./.github/actions/data-cache
       - uses: ./.github/actions/build
         with:
-          python-version: 3.14
+          python-version: "3.15"
           conan-args: --opNav True --mujoco True --rustModules True
           save-conan-cache: true
       - name: Verify Corrosion configuration
@@ -186,7 +186,7 @@ jobs:
           ]
         include:
           # An extra plain Basilisk build without optional opNav, MuJoCo, or visualization support
-          - python: "3.14"
+          - python: "3.15"
             python_label: "MAX Python"
             pytest_flags: -n auto -m "not ciSkip" -rs --timeout=300 --timeout-method=thread --durations=25 -v
             conan_args: --opNav False --mujoco False --vizInterface False

.github/workflows/requirements_dev.txt

@@ -2,6 +2,7 @@ wheel
 cmake
 conan
 packaging
+tomli; python_version < "3.11"
 setuptools
 setuptools-scm
 swig

.github/workflows/test-optional-wheels.yml

@@ -65,7 +65,7 @@ jobs:
           rust-toolchain: ${{ needs.resolve-rust-toolchain.outputs.version }}
           output-dir: ${{ matrix.output-dir }}
           conan-args: ${{ matrix.conan-args }}
-          cibw-build: cp314-*
+          cibw-build: cp315-*
           save-conan-cache: ${{ matrix.save-conan-cache }}
 
       - name: Upload wheel input
@@ -110,7 +110,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v6
         with:
-          python-version: "3.14"
+          python-version: "3.15"
 
       - name: Download core wheel input
         uses: actions/download-artifact@v6

.gitignore

@@ -56,7 +56,7 @@ supportData/EphemerisData/*.bsp
 **/tests/report/
 **/__pycache__/
 venv/
-.venv/
+.venv*/
 
 # VSCode / VS
 .devcontainer

conanfile.py

@@ -1,6 +1,7 @@
 import argparse
 import os
 import json
+import runpy
 import shutil
 import shlex
 import stat
@@ -13,12 +14,20 @@
 
 import importlib.metadata
 
+REPOSITORY_ROOT = Path(__file__).resolve().parent
+if __name__ == "__main__":
+    # Reject unsupported interpreters before loading build tools or changing files.
+    version_check = runpy.run_path(
+        str(REPOSITORY_ROOT / "src" / "buildSupport" / "checkPythonVersion.py")
+    )
+    if version_check["main"]([str(REPOSITORY_ROOT / "pyproject.toml")]):
+        sys.exit(1)
+
 from conan import ConanFile
 from conan.tools.cmake import CMakeToolchain, CMake, cmake_layout, CMakeDeps
 from conan.tools.microsoft import is_msvc
 from conan.tools.files import copy
 
-REPOSITORY_ROOT = Path(__file__).resolve().parent
 sys.path.insert(1, str(REPOSITORY_ROOT / "src" / "utilities"))
 import makeDraftModule
 
@@ -574,7 +583,7 @@ class BasiliskConan(ConanFile):
     }
 
     # Sources are located in the same place as this recipe, copy them to the recipe
-    exports_sources = "setup.py", "CMakeLists.txt", "src/*", "include/*"
+    exports_sources = "setup.py", "pyproject.toml", "CMakeLists.txt", "src/*", "include/*"
 
     for opt, value in bskModuleOptionsBool.items():
         options.update({opt: value[0]})

docs/source/Build/installBuild.rst

@@ -47,6 +47,12 @@ shown in the platform-specific installation instructions. The editable installat
 virtual environment; subsequent incremental or clean native rebuilds update the same ``dist3`` package in place and
 do not require another editable installation.
 
+Before starting build operations, ``conanfile.py`` checks the running Python version against
+``project.requires-python`` in ``pyproject.toml``. CMake checks its selected Python interpreter against
+the same range during configuration, including when invoked directly. An unsupported version stops the
+build with an error identifying the interpreter and supported range. Create or activate a virtual
+environment with a supported Python version before retrying.
+
 By default the build is for Python3 with the support for :ref:`vizInterface`
 included to enable recording data for or live-streaming to :ref:`Vizard <Vizard>`.
 

docs/source/Build/installOnLinux.rst

@@ -12,7 +12,7 @@ Software setup
 
 In order to run Basilisk, the following software will be necessary. This document outline how to install this support software.
 
--  `Python <https://www.python.org/>`__ 3.9 to 3.14.  Version 3.9 is deprecated and will be removed March 2027.
+-  Standard `CPython <https://www.python.org/>`__ 3.9 to 3.15. Version 3.9 is deprecated and will be removed March 2027.
 -  `GCC <https://gcc.gnu.org/>`__
 -  (Optional) Get the `GitKraken <https://www.gitkraken.com>`__
    application to be able to pull and manage a copy of Basilisk

docs/source/Build/installOnMacOS.rst

@@ -8,7 +8,7 @@ Setup On macOS
 ==============
 
 These instruction outline how to install Basilisk (BSK) on a clean version of macOS.
-Basilisk requires the use of Python 3.9 to 3.14.   Version 3.9 is deprecated and will be removed March 2027.
+Basilisk supports standard CPython 3.9 to 3.15. Version 3.9 is deprecated and will be removed March 2027.
 
 The following python package dependencies are automatically checked and installed in the steps below.
 

docs/source/Build/installOnWindows.rst

@@ -13,7 +13,7 @@ Software setup
 
 In order to run Basilisk, the following software will be necessary:
 
--  `Python <https://www.python.org/downloads/windows/>`__ 3.9 to 3.14.
+-  Standard `CPython <https://www.python.org/downloads/windows/>`__ 3.9 to 3.15.
    Version 3.9 is deprecated and will be removed March 2027.
 -  `pip <https://pip.pypa.io/en/stable/installing/>`__
 -  Default compiler is Visual Studios 17 2022

docs/source/Learn/bskPrinciples/bskPrinciples-6a.rst

@@ -12,6 +12,13 @@ The data importing is handled with :ref:`dataFetcher`.  This process pulls the d
 file from the local ``basilisk/supportData`` folder if it exists (repo was cloned),
 or from the ``pooch`` cache if it was downloaded by ``pooch`` data management package.
 
+Importing the data fetching tools and using local or valid cached files do not
+contact GitHub. When a file must be downloaded from Basilisk's GitHub repository,
+the downloader checks whether the installed release tag exists and falls back to
+``develop`` if it is unavailable. The tag result is cached for subsequent
+downloads in the same Python process. Files with explicit external URLs, such
+as NASA ephemeris files, do not need this tag check.
+
 At the top of your simulation script, import the data fetching tools using::
 
     from Basilisk.utilities.supportDataTools.dataFetcher import get_path, DataFile

docs/source/Support/bskKnownIssuesSnippets/1663-monte-carlo-writer-failure.rst

@@ -0,0 +1 @@
+- In Basilisk 2.12.1, a failed Monte Carlo data writer can leave incomplete combined dataframes without reporting an error to the caller; initial-condition runs can also wait indefinitely for queued data. The controller now detects writer exit, raises ``RuntimeError``, and cleans up its workers and queue manager. Treat partial archives from failed or interrupted campaigns as incomplete and rerun after resolving the writer error.

docs/source/Support/bskKnownIssuesSnippets/defer-support-data-tag-check.rst

@@ -0,0 +1,6 @@
+- In Basilisk 2.12.1, importing the support-data loader checks GitHub for a release
+  tag even when local or cached files are available, adding network-dependent
+  startup delays. The lookup is now deferred until a repository-hosted file
+  needs downloading. Local files, valid cached files, and explicit external
+  download URLs avoid the lookup; release-tag selection and the fallback to
+  ``develop`` are preserved when a download is required.

docs/source/Support/bskKnownIssuesSnippets/python-version-validation.rst

@@ -0,0 +1 @@
+- In Basilisk 2.12.1, direct ``conanfile.py`` and CMake builds could accept Python versions outside the range declared in package metadata, even though package installation rejected them. Both build paths now enforce ``project.requires-python`` from ``pyproject.toml``. For affected releases, create a virtual environment with a supported Python version before building and installing Basilisk.

docs/source/Support/bskReleaseNotesSnippets/1663-monte-carlo-pool-reuse.rst

@@ -0,0 +1 @@
+- Monte Carlo campaigns now reuse their process pool, recycling each worker after eight simulations by default. Configure worker lifetime with ``setMaxTasksPerChild()`` and bounded retention-queue capacity with ``setRetentionQueueSize()``. Writer failures now raise ``RuntimeError`` and release campaign resources, including during initial-condition reruns.

docs/source/Support/bskReleaseNotesSnippets/1663-monte-carlo-retention-delay.rst

@@ -0,0 +1 @@
+- Removed the fixed one-second delay after each Monte Carlo run queues retained data. The controller still waits for the data writer to finish before returning.

docs/source/Support/bskReleaseNotesSnippets/defer-support-data-tag-check.rst

@@ -0,0 +1 @@
+- Deferred the support-data GitHub release-tag lookup until a repository-hosted file needs downloading, eliminating this network request during imports, local and valid cached file access, and external data downloads.

docs/source/Support/bskReleaseNotesSnippets/lazy-simulation-matplotlib.rst

@@ -0,0 +1 @@
+- On Python 3.15, ``SimulationBaseClass`` defers its Matplotlib imports until plotting functionality is used, reducing startup work for simulations that do not draw diagrams. Python 3.9–3.14 retain eager imports and the same plotting interfaces.

docs/source/Support/bskReleaseNotesSnippets/python-315-support.rst

@@ -0,0 +1 @@
+- Added standard CPython 3.15 support while retaining Python 3.9 through 3.14. Python 3.15 uses NumPy 2.5.2 or newer and Numba 0.68 for examples and development; older interpreters retain their dependency ranges. Native message bindings explicitly target the NumPy 1.24 C API so Python 3.15-built wheels remain compatible with NumPy 1.24.4 on older interpreters. Updated source-build CI and wheel tooling, and moved the existing wheel installation checks to Python 3.15.

docs/source/Support/bskReleaseNotesSnippets/python-version-validation.rst

@@ -0,0 +1 @@
+- The build script now rejects unsupported Python versions before starting build operations, and CMake validates its selected interpreter against the same ``project.requires-python`` range in ``pyproject.toml``.

pyproject.toml

@@ -4,11 +4,14 @@ requires = [
     "setuptools>=77.0.3,<=84.0.0",   # Required for "bdist_wheel" to work correctly and for PEP 639 license metadata.
     "setuptools-scm>=8.0,<=10.3.4",  # Automatically include all Git-controlled files in sdist
     "packaging>=24.0,<=26.3",
+    "tomli>=2.0.1,<3; python_version < '3.11'",
 
     # needed to find the numpy include headers,
     # pin to lowest runtime allowed version to take advantage of backwards compatibility
     "numpy>=1.24.4,<2.4.0;  python_version < '3.13'",
-    "numpy>=2.0,<2.4.0;     python_version >= '3.13'",
+    "numpy>=2.0,<2.4.0;     python_version >= '3.13' and python_version < '3.15'",
+    # NumPy 2.5.2 introduced wheels for standard CPython 3.15.
+    "numpy>=2.5.2,<=2.5.4;  python_version >= '3.15'",
 
     # Requirements for building Basilisk through conanfile
     "conan>=2.4.0,<=2.33.0",
@@ -20,7 +23,7 @@ requires = [
 [project]
 name        = 'bsk'
 dynamic     = ["version", "dependencies"]
-requires-python = ">=3.9, <3.15"
+requires-python = ">=3.9, <3.16"
 
 readme      = "README.md"
 license     = "ISC"
@@ -35,6 +38,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
     "Programming Language :: Python :: Implementation :: CPython",
     "Topic :: Scientific/Engineering",
 ]
@@ -71,8 +75,9 @@ examples = [
   'scipy==1.13.1; python_version < "3.10"',
   'scipy==1.15.3; python_version >= "3.10" and python_version < "3.11"',
   'scipy>=1.17.1,<=1.18.1; python_version >= "3.11"',
-  # Match development requirements so NumPy 2.5 upgrades also update Numba.
-  'numba>=0.67.0,<=0.68.0; python_version >= "3.12"',
+  # Match development requirements for NumPy 2.5 and Python 3.15 compatibility.
+  'numba>=0.68.0,<=0.68.0; python_version >= "3.15"',
+  'numba>=0.67.0,<=0.68.0; python_version >= "3.12" and python_version < "3.15"',
   'numba<=0.68.0; python_version < "3.12"',
 ]
 opnav = [
@@ -83,9 +88,11 @@ all = [
 ]
 
 [tool.cibuildwheel]
-build = ["cp39-*", "cp310-*", "cp311-*", "cp312-*", "cp313-*", "cp314-*"]
+build = ["cp39-*", "cp310-*", "cp311-*", "cp312-*", "cp313-*", "cp314-*", "cp315-*"]
 skip  = ["*-win32", "*-musllinux_*"]
 build-verbosity = 1
+# Preserve the existing wheel checks; cibuildwheel 4 enables an ABI audit by default.
+audit-command = ""
 before-build = "python .github/scripts/configure_conan_retries.py && pip install \"libclang>=15.0.6.1,<=18.1.1\" ninja"
 test-extras = ["test"]
 test-command = "bskLargeData && pytest -v {project}/src/tests -m \"not ciSkip and not scenarioTest\""

requirements.txt

@@ -1,7 +1,8 @@
 pandas>=2.0.3,<=3.0.6
 matplotlib>=3.7.5,<=3.11.2
 numpy>=1.24.4,<=2.5.4; python_version < "3.13"
-numpy>=2.0,<=2.5.4; python_version >= "3.13"
+numpy>=2.0,<=2.5.4; python_version >= "3.13" and python_version < "3.15"
+numpy>=2.5.2,<=2.5.4; python_version >= "3.15"
 colorama==0.4.6
 tqdm>=4.67.3,<=4.70.1
 pillow>=10.4.0,<=13.0.0

requirements_dev.txt

@@ -2,13 +2,16 @@ wheel>=0.45.1,<=0.48.0
 cmake>=3.26,<=4.4.4
 conan>=2.4.0,<=2.33.0
 packaging>=24,<=26.3
+tomli>=2.0.1,<3; python_version < "3.11"
 setuptools>=70.1.0,<=84.0.0
 setuptools-scm>=8.0,<=10.3.4
 swig>=4.4.1,<5
 libclang>=15.0.6.1,<=18.1.1
 
 # NumPy 2.5 is available on Python 3.12+ and requires Numba 0.67 or newer.
-numba>=0.67.0,<=0.68.0; python_version >= "3.12"
+# Python 3.15 requires Numba 0.68; older Python versions retain their choices.
+numba>=0.68.0,<=0.68.0; python_version >= "3.15"
+numba>=0.67.0,<=0.68.0; python_version >= "3.12" and python_version < "3.15"
 numba<=0.68.0; python_version < "3.12"
 
 pytest>=8.3.5,<=9.1.1

src/CMakeLists.txt

@@ -70,10 +70,10 @@ list(FILTER BSK_CUSTOM_CMAKE_FILES INCLUDE REGEX "(^|/)Custom\\.cmake$")
 # Find necessary packages
 find_package(Python3 ${PYTHON_VERSION} EXACT REQUIRED COMPONENTS Interpreter Development.Module OPTIONAL_COMPONENTS Development.SABIModule)
 
-# enforce minimum supported Python version and warn on deprecated versions
-if(Python3_VERSION VERSION_LESS "3.9")
-    message(FATAL_ERROR "Basilisk requires Python 3.9 or newer, but found Python ${Python3_VERSION}.")
-elseif(Python3_VERSION VERSION_LESS "3.10")
+# Enforce the package's supported Python range and warn on deprecated versions.
+include(bskCheckPythonVersion)
+bsk_check_python_version("${CMAKE_CURRENT_SOURCE_DIR}/../pyproject.toml")
+if(Python3_VERSION VERSION_LESS "3.10")
     message(WARNING "You are using Python ${Python3_VERSION}, but support for Python 3.9 is deprecated and will be removed in March 2027.")
 endif()
 

src/architecture/messaging/_UnitTest/test_numpy_api_compatibility.py

@@ -0,0 +1,54 @@
+# ISC License
+#
+# Copyright (c) 2026, Autonomous Vehicle Systems Lab, University of Colorado at Boulder
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""Check the NumPy C API required by the shared message bindings."""
+
+from pathlib import Path
+import re
+import sysconfig
+
+import numpy as np
+from setuptools._distutils.ccompiler import new_compiler
+from setuptools._distutils.sysconfig import customize_compiler
+
+
+def test_message_bindings_support_numpy124(tmp_path):
+    """Compile the real NumPy include block against the installed build headers.
+
+    Newer headers must not silently raise the runtime requirement above NumPy
+    1.24, even when the runtime executing this test is newer.
+    """
+    template = (Path(__file__).parents[1] / "newMessaging.ih").read_text(encoding="utf-8")
+    numpy_blocks = [
+        block for block in re.findall(r"%\{(.*?)%\}", template, flags=re.DOTALL)
+        if "#include <numpy/arrayobject.h>" in block
+    ]
+    assert len(numpy_blocks) == 1
+    source = tmp_path / "numpy_api_probe.cpp"
+    source.write_text(
+        numpy_blocks[0]
+        + '\nstatic_assert(NPY_FEATURE_VERSION <= NPY_1_24_API_VERSION, '
+        '"Message bindings must support the NumPy 1.24 runtime");\n',
+        encoding="utf-8",
+    )
+    compiler = new_compiler()
+    customize_compiler(compiler)
+    compiler.compile(
+        [str(source)],
+        output_dir=str(tmp_path),
+        include_dirs=[sysconfig.get_path("include"), np.get_include()],
+        macros=[("Py_LIMITED_API", "0x03090000")],
+    )