fix: correct dtypes for numpy v2 (#3159)

* fix: import numpy for tests

* fix: use the platform integer type

* fix: use type

* fix: np.intp type

* fix: only for numpy 2+

* fix: remove duplicate workflows and test windows with numpy v1.xx

* fix: add coverage

* fix: remove duplicate test

.github/workflows/test.yml

@@ -53,6 +53,10 @@ jobs:
             python-architecture: x86
             runs-on: windows-latest
             dependencies-kind: full
+          - python-version: '3.9'
+            python-architecture: x86
+            runs-on: windows-latest
+            dependencies-kind: numpy1
           - python-version: '3.8'
             python-architecture: x64
             runs-on: ubuntu-latest
@@ -61,18 +65,6 @@ jobs:
             python-architecture: x64
             runs-on: ubuntu-latest
             dependencies-kind: pypy
-          - python-version: '3.11'
-            python-architecture: x64
-            runs-on: ubuntu-latest
-            dependencies-kind: numpy2
-          - python-version: '3.11'
-            python-architecture: x64
-            runs-on: macos-11
-            dependencies-kind: numpy2
-          - python-version: '3.11'
-            python-architecture: x64
-            runs-on: windows-latest
-            dependencies-kind: numpy2
 
     runs-on: ${{ matrix.runs-on }}
 

dev/generate-tests.py

@@ -425,6 +425,7 @@ def genspectests(specdict):
 """
             )
             f.write("import pytest\nimport kernels\n\n")
+            f.write("import pytest\nimport numpy as np\nimport kernels\n\n")
             num = 1
             if spec.tests == []:
                 f.write(

requirements-test-numpy1.txt

@@ -0,0 +1,4 @@
+numpy<2.0.0
+pytest>=6
+pytest-cov
+pytest-xdist

src/awkward/_reducers.py

@@ -62,7 +62,9 @@ def _dtype_for_kernel(cls, dtype: DTypeLike) -> DTypeLike:
         else:
             return dtype
 
-    _use32 = (ak._util.win or ak._util.bits32) and not ak._util.numpy2
+    _use32 = ((ak._util.win or ak._util.bits32) and not ak._util.numpy2) or (
+        ak._util.numpy2 and np.intp is np.int32
+    )
 
     @classmethod
     def _promote_integer_rank(cls, given_dtype: DTypeLike) -> DTypeLike: