BLD: Allow building with NumPy nightlies and use it for nightlies

.circleci/config.yml

@@ -49,7 +49,12 @@ jobs:
           no_output_timeout: 30m # Sometimes the tests won't generate any output, make sure the job doesn't get killed by that
           command: |
             pip3 install cibuildwheel==2.15.0
+            # When this is a nightly wheel build, allow picking up NumPy 2.0 dev wheels:
+            if [[ "$IS_SCHEDULE_DISPATCH" == "true" || "$IS_PUSH" != 'true' ]]; then
+                export CIBW_ENVIRONMENT="PIP_EXTRA_INDEX_URL=https://pypi.anaconda.org/scientific-python-nightly-wheels/simple"
+            fi
             cibuildwheel --prerelease-pythons --output-dir wheelhouse
+
           environment:
             CIBW_BUILD: << parameters.cibw-build >>
 

.github/workflows/wheels.yml

@@ -137,14 +137,27 @@ jobs:
         shell: bash -el {0}
         run: echo "sdist_name=$(cd ./dist && ls -d */)" >> "$GITHUB_ENV"
 
-      - name: Build wheels
+      - name: Build normal wheels
+        if: ${{ (env.IS_SCHEDULE_DISPATCH != 'true' || env.IS_PUSH == 'true') }}
         uses: pypa/cibuildwheel@v2.16.2
         with:
          package-dir: ./dist/${{ matrix.buildplat[1] == 'macosx_*' && env.sdist_name || needs.build_sdist.outputs.sdist_file }}
         env:
           CIBW_PRERELEASE_PYTHONS: True
           CIBW_BUILD: ${{ matrix.python[0] }}-${{ matrix.buildplat[1] }}
 
+      - name: Build nightly wheels (with NumPy pre-release)
+        if: ${{ (env.IS_SCHEDULE_DISPATCH == 'true' && env.IS_PUSH != 'true') }}
+        uses: pypa/cibuildwheel@v2.16.2
+        with:
+         package-dir: ./dist/${{ matrix.buildplat[1] == 'macosx_*' && env.sdist_name || needs.build_sdist.outputs.sdist_file }}
+        env:
+          # The nightly wheels should be build witht he NumPy 2.0 pre-releases
+          # which requires the additional URL.
+          CIBW_ENVIRONMENT: PIP_EXTRA_INDEX_URL=https://pypi.anaconda.org/scientific-python-nightly-wheels/simple
+          CIBW_PRERELEASE_PYTHONS: True
+          CIBW_BUILD: ${{ matrix.python[0] }}-${{ matrix.buildplat[1] }}
+
       - name: Set up Python
         uses: mamba-org/setup-micromamba@v1
         with:

pyproject.toml

@@ -6,11 +6,12 @@ requires = [
     "meson==1.2.1",
     "wheel",
     "Cython>=0.29.33,<3",  # Note: sync with setup.py, environment.yml and asv.conf.json
-    # Note: numpy 1.25 has a backwards compatible C API by default
-    # we don't want to force users to compile with 1.25 though
-    # (Ideally, in the future, though, oldest-supported-numpy can be dropped when our min numpy is 1.25.x)
-    "oldest-supported-numpy>=2022.8.16; python_version<'3.12'",
-    "numpy>=1.26.0,<2; python_version>='3.12'",
+    # Any NumPy version should be fine for compiling.  Users are unlikely
+    # to get a NumPy<1.25 so the result will be compatible with all relevant
+    # NumPy versions (if not it is presumably compatible with their version).
+    # Pin <2.0 for releases until tested against an RC.  But explicitly allow
+    # testing the `.dev0` nightlies (which require the extra index).
+    "numpy>1.22.4,<=2.0.0.dev0",
     "versioneer[toml]"
 ]