Bump minimum required python and nanobind versions

RELEASE-NOTES.md

@@ -101,6 +101,7 @@ The Axom project release numbers follow [Semantic Versioning](http://semver.org/
   internal `quest::internal::read_*_mesh()`/`logger_init()` helpers are now declared only when Axom is
   configured with MPI. Serial code that passed the placeholder `MPI_COMM_SELF` explicitly should drop the argument.
 - We can now configure Axom without MPI when some of its dependencies were configured with MPI.
+- Python: Raised the minimum supported versions for Python bindings to Python 3.9 and nanobind 2.10.
 - Quest: Status-returning reader/writer operations in `C2CReader`, `MFEMReader`, `ProEReader`,
   `STEPReader`, `STLReader`, `STLWriter`, and their parallel variants are now marked `[[nodiscard]]`.
   Callers that previously ignored returned status values must check them to avoid compiler diagnostics.

scripts/spack/packages/axom/package.py

@@ -299,12 +299,12 @@ class Axom(CachedCMakePackage, CudaPackage, ROCmPackage):
 
     # Python
     with when("+python"):
-        depends_on("python")
+        depends_on("python@3.9:")
 
         # extending python allows spack environment views to import axom from python
         extends("python")
 
-        depends_on("py-nanobind@2.7.0:")
+        depends_on("py-nanobind@2.10.0:")
         depends_on("py-pytest")
         depends_on("py-packaging")
         depends_on("py-pygments")

src/axom/sidre/nanobind_sidre.cpp

@@ -674,8 +674,7 @@ NB_MODULE(_sidre, m_sidre)
   m_sidre.attr("AXOM_ENABLE_MPI") = false;
 #endif
 
-#if defined(AXOM_USE_MPI) && \
-  ((NB_VERSION_MAJOR > 2) || (NB_VERSION_MAJOR == 2 && NB_VERSION_MINOR >= 10))
+#if defined(AXOM_USE_MPI)
   m_sidre.attr("AXOM_HAS_DISTRIBUTED_BLUEPRINT_INDEX_BINDING") = true;
 #else
   m_sidre.attr("AXOM_HAS_DISTRIBUTED_BLUEPRINT_INDEX_BINDING") = false;
@@ -833,9 +832,7 @@ NB_MODULE(_sidre, m_sidre)
          nb::keep_alive<0, 1>(),
          "Return an iterator over Attributes")
 
-#if defined(AXOM_USE_MPI) && \
-  ((NB_VERSION_MAJOR > 2) || (NB_VERSION_MAJOR == 2 && NB_VERSION_MINOR >= 10))
-    // Distributed Blueprint index generation builds cleanly under nanobind >= 2.10
+#if defined(AXOM_USE_MPI)
     .def(
       "generateBlueprintIndex",
       [](DataStore& self,

src/axom/sidre/tests/sidre_spio_Py.py

@@ -120,8 +120,7 @@ def test_iomanager_split_communicator(tmp_path):
 
 
 def test_distributed_generate_blueprint_index(tmp_path):
-    # The distributed generateBlueprintIndex overload is built only under
-    # nanobind >= 2.10; skip cleanly if this build omitted it.
+    # The distributed generateBlueprintIndex overload is built only with MPI.
     if not sidre.AXOM_HAS_DISTRIBUTED_BLUEPRINT_INDEX_BINDING:
         pytest.skip("generateBlueprintIndex not bound")
 

src/cmake/thirdparty/SetupAxomThirdParty.cmake

@@ -308,7 +308,7 @@ if(EXISTS ${Python_EXECUTABLE})
       set(DEV_MODULE Development.Module)
     endif()
 
-    find_package(Python 3.8 COMPONENTS Interpreter ${DEV_MODULE} REQUIRED)
+    find_package(Python 3.9 COMPONENTS Interpreter ${DEV_MODULE} REQUIRED)
 
     # Debug print the paths to the found Python artifacts
     message(STATUS "Python version: ${Python_VERSION}")
@@ -441,7 +441,7 @@ if(nanobind_ROOT
    AND NOT AXOM_ENABLE_UBSAN)
 
     axom_assert_is_directory(DIR_VARIABLE nanobind_ROOT)
-    find_package(nanobind CONFIG REQUIRED)
+    find_package(nanobind 2.10 CONFIG REQUIRED)
     message(STATUS "Nanobind support is ON")
     set(NANOBIND_FOUND TRUE)
 else()

src/docs/sphinx/quickstart_guide/config_build.rst

@@ -31,7 +31,7 @@ Basic requirements:
     a minimum version of 3.18 when building with CUDA support,
     and a minimum version of 3.21 when building with HIP support
   * Fortran Compiler (optional)
-  * Python 3.8 at a minimum for python bindings (optional)
+  * Python 3.9 at a minimum for python bindings (optional)
 
 Supported Compilers
 ~~~~~~~~~~~~~~~~~~~