[python] update the python build

python/CMakeLists.txt

@@ -61,8 +61,7 @@ target_include_directories(_mir PRIVATE ${PROJECT_SOURCE_DIR}/src ${PROJECT_BINA
 target_link_libraries(_mir PRIVATE mir)
 target_compile_definitions(_mir PRIVATE NPY_NO_DEPRECATED_API=NPY_1_7_API_VERSION)
 
-# _mir.so installs at site-packages root (not inside mir/) — matches setup.py Extension("_mir")
-install(TARGETS _mir DESTINATION ${MIR_PYTHON_INSTALL_DIR} COMPONENT python)
+install(TARGETS _mir DESTINATION ${MIR_PYTHON_INSTALL_DIR}/mir COMPONENT python)
 install(FILES
     mir/src/mir/__init__.py
     mir/src/mir/griddef.py

python/mir/pyproject.toml

@@ -32,8 +32,9 @@ classifiers = [
 	"Operating System :: MacOS",
 	"Topic :: Scientific/Engineering",
 ]
-dependencies = ["eckit", "findlibs", "numpy", "pyyaml", "scipy"]
-dynamic = ["version"]
+# NOTE don't list `dependencies` in this file, use setup.py instead
+dynamic = ["version", "dependencies"]
+
 
 [project.scripts]
 mir-weight-matrix-convert = "mir.tools.weight_matrix_convert:main"
@@ -44,3 +45,4 @@ version = {file = "VERSION"}
 
 [tool.setuptools.packages.find]
 where = ["src"]
+exclude = ["_mir*"]

python/mir/setup.py

@@ -0,0 +1,38 @@
+import os
+from setuptools import setup
+import platform
+from wheel.bdist_wheel import bdist_wheel
+import sys
+
+with open('VERSION', 'r') as fVersion:
+    version = fVersion.readlines()[0].strip()
+install_requires = [
+    f"mirlib=={version}",
+    f"eckit=={version}",
+    "findlibs",
+    "numpy>=2.0,<3.0", # NOTE may need tighter range in case of ABI issues. Dont forget to keep in sync with pre-compile.sh (or cmake files if numpy install refactored)
+    "scipy",
+    "pyyaml",
+]
+
+# NOTE see ci-utils/wheelmaker/buildscripts/setup_utils, we need to get the right abi compat tag
+class bdist_wheel_ext(bdist_wheel):
+    def get_tag(self):
+        python, abi, plat = bdist_wheel.get_tag(self)
+        return python, abi, f"manylinux_2_28_{platform.machine()}"
+
+
+ext_kwargs = {
+    "darwin": {},
+    "linux": {"cmdclass": {"bdist_wheel": bdist_wheel_ext}},
+}
+
+setup(
+    version=version,
+    package_data={
+        "": ["*.so"],
+    },
+    has_ext_modules=lambda: True,
+    install_requires=install_requires,
+    **ext_kwargs[sys.platform],
+)

python/mir/src/mir/__init__.py

@@ -8,16 +8,12 @@
 # does it submit to any jurisdiction.
 
 
-from ctypes import CDLL
-
-# init section -- ensure libmir.so is loaded, utilizing findlibs instead of relying on rpath
 import findlibs
 
-m = findlibs.find("mir")
-CDLL(m)
+findlibs.load("mir")
 
-from _mir import *
 from eckit.geo import Grid
+from mir._mir import *
 
-__version__ = version()
+__lib_version__ = version()
 __git_sha1__ = git_sha1()

python/mirlib/buildconfig

@@ -11,6 +11,8 @@
 # TODO we duplicate information -- pyproject.toml's `name` and `packages` are derivable from $NAME and must stay consistent
 
 NAME="mir"
-CMAKE_PARAMS="-Deckit_ROOT=/tmp/mir/prereqs/eckitlib -Deccodes_ROOT=/tmp/mir/prereqs/eccodeslib -Datlas_ROOT=/tmp/mir/prereqs/atlaslib-ecmwf -DENABLE_ECKIT_GEO=1"
+_HERE="$(dirname -- "$(readlink -f -- "${BASH_SOURCE[0]}")")"
+PYTHON_INSTALL_DIR=$(cd -- "$_HERE/../mir/src" && pwd) # dont use readlink -m here, not macos portable
+CMAKE_PARAMS="-Deckit_ROOT=/tmp/mir/prereqs/eckitlib -Deccodes_ROOT=/tmp/mir/prereqs/eccodeslib -Datlas_ROOT=/tmp/mir/prereqs/atlaslib-ecmwf -DENABLE_ECKIT_GEO=1 -DENABLE_PYTHON=1 -DMIR_PYTHON_INSTALL_DIR=$PYTHON_INSTALL_DIR -DPython3_FIND_VIRTUALENV=ONLY"
 PYPROJECT_DIR="python/mirlib"
 DEPENDENCIES='["eccodeslib", "eckitlib", "atlaslib-ecmwf"]'

python/mirlib/pre-compile.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+# python bindings are built via cmake, as part of the overall compile.sh action
+# this requires numpy present -- but currently the cmake files only check
+# numpy presence, dont pip install it on its own. Hence we hack the install here
+
+uv pip install 'numpy>=2.0,<3.0' cython