Merge pull request numpy#27202 from seberg/issue-27194

BUG: Fix NPY_RAVEL_AXIS on backwards compatible NumPy 2 builds

Author: charris

numpy/_core/include/numpy/npy_2_compat.h

@@ -125,7 +125,7 @@ PyArray_ImportNumPyAPI(void)
     #define NPY_DEFAULT_INT  \
         (PyArray_RUNTIME_VERSION >= NPY_2_0_API_VERSION ? NPY_INTP : NPY_LONG)
     #define NPY_RAVEL_AXIS  \
-        (PyArray_RUNTIME_VERSION >= NPY_2_0_API_VERSION ? -1 : 32)
+        (PyArray_RUNTIME_VERSION >= NPY_2_0_API_VERSION ? NPY_MIN_INT : 32)
     #define NPY_MAXARGS  \
         (PyArray_RUNTIME_VERSION >= NPY_2_0_API_VERSION ? 64 : 32)
 #endif

numpy/_core/tests/examples/cython/checks.pyx

@@ -129,6 +129,10 @@ def get_default_integer():
         return cnp.dtype("intp")
     return None
 
+def get_ravel_axis():
+    return cnp.NPY_RAVEL_AXIS
+
+
 def conv_intp(cnp.intp_t val):
     return val
 

numpy/_core/tests/test_cython.py

@@ -153,6 +153,13 @@ def test_default_int(install_temp):
 
     assert checks.get_default_integer() is np.dtype(int)
 
+
+def test_ravel_axis(install_temp):
+    import checks
+
+    assert checks.get_ravel_axis() == np.iinfo("intc").min
+
+
 def test_convert_datetime64_to_datetimestruct(install_temp):
     # GH#21199
     import checks