Merge pull request #3739 from davidhewitt/pypy-buffer-hidden-fields

fix size of pypy private fields in Py_buffer definition

.github/workflows/build.yml

@@ -32,6 +32,7 @@ jobs:
         with:
           python-version: ${{ inputs.python-version }}
           architecture: ${{ inputs.python-architecture }}
+          check-latest: ${{ startsWith(inputs.python-version, 'pypy') }}  # PyPy can have FFI changes within Python versions, which creates pain in CI
 
       - name: Install nox
         run: python -m pip install --upgrade pip && pip install nox

pyo3-ffi/src/cpython/object.rs

@@ -21,7 +21,7 @@ mod bufferinfo {
     use std::ptr;
 
     #[cfg(PyPy)]
-    const Py_MAX_NDIMS: usize = 36;
+    const Py_MAX_NDIMS: usize = if cfg!(Py_3_9) { 64 } else { 36 };
 
     #[repr(C)]
     #[derive(Copy, Clone)]