Merge pull request scipy#19849 from rgommers/fix-prerelease-job

CI: fix prerelease job to use numpy 2.0, and add a second job to test ABI compat

.github/workflows/linux_meson.yml

@@ -279,7 +279,9 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.9]
+        # Both use numpy 2.0-dev at build time; 3.9 job then downgrades to
+        # lowest supported NumPy version in order to test ABI compatibility.
+        python-version: ['3.9', '3.11']
 
     steps:
     - uses: actions/checkout@v3
@@ -306,11 +308,15 @@ jobs:
     - name: Install Python packages
       run: |
         python -m pip install cython pythran ninja meson-python pybind11 click rich_click pydevtool
-        python -m pip install --pre --upgrade --timeout=60 -i https://pypi.anaconda.org/scientific-python-nightly-wheels/simple numpy
-        python -m pip install --pre --upgrade pytest pytest-cov pytest-xdist mpmath gmpy2 threadpoolctl pooch matplotlib hypothesis
+        # Note: matplotlib not installed here to avoid issues around numpy 2.0
+        # (it can be put back after matplotlib has made a 2.0-compatible
+        # release on PyPI.
+        python -m pip install --pre --upgrade pytest pytest-cov pytest-xdist mpmath gmpy2 threadpoolctl pooch hypothesis
         # TODO: once the scipy_ symbol prefix issue is fixed, install
         # scipy-openblas32 from the pre-releases bucket again (see gh-19640)
         python -m pip install "scipy-openblas32<=0.3.23.293.2"
+        # Install numpy last, to ensure we get 2.0.0-dev (avoid possible <2.0 constraints).
+        python -m pip install --pre --upgrade --timeout=60 -i https://pypi.anaconda.org/scientific-python-nightly-wheels/simple numpy
 
     - name:  Prepare compiler cache
       id:    prep-ccache
@@ -339,10 +345,15 @@ jobs:
       shell: bash -l {0}
       run: ccache -s
 
+    - name: Downgrade NumPy from 2.0-dev to lowest supported
+      if: matrix.python-version == '3.9'
+      run: |
+        python -m pip install "numpy==1.22.4"
+
     - name: Test SciPy
       run: |
         export OPENBLAS_NUM_THREADS=1
-        python dev.py test -j2 --mode full -- --cov --cov-report term-missing 
+        python dev.py --no-build test -j2 --mode full -- --cov --cov-report term-missing
 
   #################################################################################
   linux_32bit:

scipy/signal/tests/test_filter_design.py

@@ -1563,7 +1563,7 @@ def test_invalid_input(self):
         assert "gstop should be larger than 0.0" in str(exc_info.value)
 
     def test_runtime_warnings(self):
-        msg = "Order is zero.*|divide by zero encountered in divide"
+        msg = "Order is zero.*|divide by zero encountered"
         with pytest.warns(RuntimeWarning, match=msg):
             buttord(0.0, 1.0, 3, 60)