Port from pybind11 to nanobind

.github/actions/setup-build-env/action.yml

@@ -7,7 +7,7 @@ inputs:
     required: true
   install-build-backend:
     description: >
-      Whether to pre-install pybind11, scikit-build-core and numpy into the
+      Whether to pre-install nanobind, scikit-build-core into the
       host environment. Required for `--no-build-isolation` builds; can be
       skipped when pip provisions an isolated build environment.
     required: false
@@ -63,4 +63,4 @@ runs:
     - name: Install Python build backend (for --no-build-isolation builds)
       if: inputs.install-build-backend == 'true'
       shell: bash
-      run: python -m pip install pybind11 scikit-build-core numpy
+      run: python -m pip install nanobind scikit-build-core

.github/actions/verify-atlas4py/action.yml

@@ -23,5 +23,5 @@ runs:
     - name: Run pytest suite
       shell: bash
       run: |
-        python -m pip install pytest
+        python -m pip install pytest numpy
         pytest -v tests

pyproject.toml

@@ -2,17 +2,15 @@
 build-backend = 'scikit_build_core.build'
 requires = [
     'scikit-build-core>=0.10.7',
-    'pybind11>=2.11.1',
+    'nanobind>=2.11.0',
 ]
 
 [project]
-dependencies = [
-  'numpy>=1.23'
-]
+dependencies = []
 
 description = 'Python bindings for Atlas: a ECMWF library for parallel data-structures'
 name = 'atlas4py'
-version = '0.41.1.dev3' # <major>.<minor>.<patch>.dev<dev> : <atlas.major>.<atlas.minor>.<atlas.patch>.dev<atlas4py.dev>
+version = '0.41.1.dev4' # <major>.<minor>.<patch>.dev<dev> : <atlas.major>.<atlas.minor>.<atlas.patch>.dev<atlas4py.dev>
 license = {text = "Apache License 2.0"}
 readme = {file = 'README.md', content-type = 'text/markdown'}
 authors = [{email = 'willem.deconinck@ecmwf.int'}, {name = 'Willem Deconinck'}]
@@ -35,7 +33,7 @@ classifiers = [
 repository = 'https://github.com/GridTools/atlas4py'
 
 [project.optional-dependencies]
-test = ['pytest']
+test = ['pytest','numpy>=1.23']
 
 [tool.scikit-build]
 minimum-version = '0.5'

requirements-dev.txt

@@ -1,6 +1,6 @@
 black>=21.12b0
 bump-my-version>=1.2.6
-numpy>=1.17
+numpy>=1.23
 pytest>=6.1
 tox>=4.0
 build>=1.2.2

src/atlas4py/CMakeLists.txt

@@ -19,7 +19,7 @@ if (NOT SKBUILD)
     following command that avoids a costly creation of a new virtual
     environment at every compilation:
     =====================================================================
-    $ pip install pybind11 scikit-build-core
+    $ pip install nanobind scikit-build-core
     $ pip install --no-build-isolation -ve ${PROJECT_ROOT_DIR}
     =====================================================================
     You may optionally add -Ceditable.rebuild=true to auto-rebuild when
@@ -49,12 +49,19 @@ set(CMAKE_CXX_STANDARD 17)
 include(cmake/atlas4py_add_atlas.cmake)
 atlas4py_add_atlas()
 
-### Find pybind11
+### Find nanobind
 
-message( STATUS "${PROJECT_NAME}: find_package(pybind11 CONFIG)..." )
-find_package(pybind11 CONFIG)
-if (NOT pybind11_FOUND)
-    message( FATAL_ERROR "pybind11 not found. Please install pybind11 or use pip to install this package." )
+message( STATUS "${PROJECT_NAME}: find_package(Python 3.9 REQUIRED COMPONENTS Interpreter Development.Module)" )
+find_package(Python 3.9 REQUIRED COMPONENTS Interpreter Development.Module)
+
+execute_process(
+  COMMAND "${Python_EXECUTABLE}" -m nanobind --cmake_dir
+  OUTPUT_STRIP_TRAILING_WHITESPACE OUTPUT_VARIABLE nanobind_ROOT)
+
+message( STATUS "${PROJECT_NAME}: find_package(nanobind CONFIG)..." )
+find_package(nanobind CONFIG)
+if (NOT nanobind_FOUND)
+    message( FATAL_ERROR "nanobind not found. Please install nanobind or use pip to install this package." )
 endif()
 
 ### RPATH handling
@@ -74,7 +81,7 @@ endif()
 
 ### Python bindings module atlas4py
 
-pybind11_add_module(_atlas4py _atlas4py.cpp)
+nanobind_add_module(_atlas4py _atlas4py.cpp)
 target_link_libraries(_atlas4py PUBLIC atlas)
 target_compile_definitions(_atlas4py PRIVATE ATLAS4PY_VERSION_STRING=${PROJECT_VERSION_FULL})