PyPy 3.12 is missing c_int

[mattip]

Bug Description

In PR #5547 the addition of PyDict_ClearWatcher needs c_int. But it is conditionally removed for pypy 3.12 in pyo3-ffi/src/cpython/dictobject.rs. Now that I am testing pyO3 on pypy3.12 in preparation for a first 3.12 release, I see the failure.

Steps to Reproduce

1. Download a nightly pypy3.12
2. run pyo3 tests

Backtrace

Error[E0425]: cannot find type `c_int` in this scope
   --> pyo3-ffi/src/cpython/dictobject.rs:134:44
    |
134 |     pub fn PyDict_ClearWatcher(watcher_id: c_int) -> c_int;
    |                                            ^^^^^ not found in this scope
    |
note: found an item that was configured out
   --> pyo3-ffi/src/cpython/abstract_.rs:5:16
    |
  4 | #[cfg(not(Py_3_11))]
    |          --------- the item is gated here
  5 | use core::ffi::c_int;
    |                ^^^^^
note: found an item that was configured out
   --> pyo3-ffi/src/cpython/dictobject.rs:14:16
    |
 13 | #[cfg(all(not(PyPy), Py_3_12))]
    |              ------ the item is gated here
 14 | use core::ffi::c_int;
    |                ^^^^^
help: consider importing one of these type aliases
    |
  1 + use std::ffi::c_int;
    |
  1 + use std::os::raw::c_int;
    |
  1 + use core::ffi::c_int;
    |
  1 + use libc::c_int;

Your operating system and version

Ubuntu linux-x86_64 24.04

Your Python version (python --version)

pypy3.12

Your Rust version (rustc --version)

rustc 1.98.0 (88d9e12ae 2026-08-18)

Your PyO3 version

HEAD

How did you install python? Did you use a virtualenv?

downloaded nightly build

Additional Info

I am not a rust expert, but I think the problem is

pyo3/pyo3-ffi/src/cpython/dictobject.rs

Lines 13 to 15 in e2b68f3

	#[cfg(all(not(PyPy), Py_3_12))]
	use core::ffi::c_int;

[chirizxc]

We also need update

pyo3/pyo3-ffi/Cargo.toml

Lines 56 to 58 in 8e0c853

	[package.metadata.pypy]
	min-version = "3.11"
	max-version = "3.11" # inclusive

pyo3/pyo3-ffi/build.rs

Lines 25 to 31 in 27a6f1a

	const SUPPORTED_VERSIONS_PYPY: SupportedVersions = SupportedVersions {
	min: PythonVersion {
	major: 3,
	minor: 11,
	},
	max: SUPPORTED_VERSIONS_CPYTHON.max,
	};

pyo3/pyo3-ffi/build.rs

Lines 116 to 129 in 27a6f1a

	PythonImplementation::PyPy => {
	let versions = SUPPORTED_VERSIONS_PYPY;
	ensure!(
	interpreter_config.target_abi().version() >= versions.min,
	"the configured PyPy interpreter version ({}) is lower than PyO3's minimum supported version ({})",
	interpreter_config.target_abi().version(),
	versions.min,
	);
	// PyO3 does not support abi3, so we cannot offer forward compatibility
	if interpreter_config.target_abi().version() > versions.max {
	let error = MaximumVersionExceeded::new(interpreter_config, versions.max);
	return Err(error.finish().into());
	}
	}

- #[cfg(all(not(PyPy), Py_3_12))]
+ #[cfg(all(not(PyPy_3_11), Py_3_12))]
  use core::ffi::c_int;

+PythonImplementation::PyPy => {
+    out.push("cargo:rustc-cfg=PyPy".to_owned());
+    for i in MINIMUM_SUPPORTED_VERSION_PYPY.minor..=self.target_abi.version().minor {
+        out.push(format!("cargo:rustc-cfg=PyPy_3_{i}"));
+    }
+}