Improve test coverage.

Update scripts to use actions/setup-python to install different Python
versions.  Add run-faber.sh and get-py-env.py scripts.  Add
test-ubuntu-py-ver.yml CI script to test with different Python versions.

.github/get-py-env.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+#
+# Determine info about the Python install and write shell code to stdout, to
+# set env variables.  This will set the variables PY_LDFLAGS, PY_CFLAGS and
+# PY_INC_PATH.
+#
+# The python3-config tool is used as the source of this info. In theory we
+# could use sysconfig as well but the setup-python action from github appears
+# to patch python3-config but not patch the sysconfig info.
+#
+# Usage:
+#   eval $(python3 get-py-env.py)
+
+import os
+import re
+import subprocess
+
+
+def get_output(cmd):
+    rv = subprocess.run(
+        cmd,
+        capture_output=True,  # Capture stdout and stderr
+        text=True,  # Decode output as text (UTF-8)
+        check=True,  # Raise an error if the command fails
+    )
+    return rv.stdout
+
+
+def extract_flags(cmd, prefix):
+    flags = []
+    for part in get_output(cmd).split():
+        part = part.strip()
+        if part.startswith(prefix):
+            flags.append(part)
+    return ' '.join(flags)
+
+
+def find_python_h():
+    """Find the include path that has Python.h contained inside.
+    We could use INCLUDEPY from sysconfig but github patches
+    python3-config but not the sysconfig info (after moving the
+    install).
+    """
+    c_flags = extract_flags(['python3-config', '--cflags'], '-I')
+    for part in c_flags.split():
+        m = re.search(r'-I(\S+)', part)
+        if not m:
+            continue
+        inc_path = m.group(1)
+        if os.path.exists(os.path.join(inc_path, 'Python.h')):
+            return inc_path
+    raise SystemExit('cannot find Python.h')
+
+
+def main():
+    ld_flags = extract_flags(['python3-config', '--ldflags'], '-L')
+    c_flags = extract_flags(['python3-config', '--cflags'], '-I')
+    include_path = find_python_h()
+    print(f'PY_LDFLAGS="{ld_flags}"')
+    print(f'PY_CFLAGS="{c_flags}"')
+    print(f'PY_INC_PATH="{include_path}"')
+
+
+if __name__ == '__main__':
+    main()

.github/run-faber.sh

@@ -0,0 +1,46 @@
+#!/bin/sh
+
+set -eu
+
+echo "cxx version: $CXX $($CXX --version)"
+echo "cxx std: $CXX_STD"
+echo "python3 path: $(which python3)"
+echo "python3 version: $(python3 --version)"
+
+if ! which faber > /dev/null; then
+    echo "Installing faber..."
+    python3 -m pip install --upgrade pip
+    python3 -m pip install -U faber
+fi
+echo "faber version: $(faber -v)"
+
+# find and set PY_LDFLAGS and PY_INC_PATH
+eval $(python3 .github/get-py-env.py)
+
+echo "PY_INC_PATH=$PY_INC_PATH"
+echo "PY_LDFLAGS=$PY_LDFLAGS"
+
+case $(python3-config --abiflags) in
+    *t*)
+        # When running with free-threaded, we always want to disable the GIL
+        # even for extensions without the mod_gil_not_used() flag
+        export PYTHON_GIL=0
+        ;;
+esac
+
+# this could be set by LD_LIBRARY_PATH but faber overrides it
+prefix=$(python3-config --prefix)
+echo "${prefix}/lib" > /etc/ld.so.conf.d/boost-ci.conf && ldconfig
+
+sed -e "s/\$PYTHON/python3/g" .ci/faber > $HOME/.faber
+
+faber \
+  --with-boost-include=${BOOST_PY_DEPS} \
+  --builddir=build \
+  cxx.name="${CXX}" \
+  cxxflags="-std=${CXX_STD}" \
+  cppflags="-std=${CXX_STD}" \
+  include="${PY_INC_PATH}" \
+  ldflags="${PY_LDFLAGS}" \
+  -j`nproc` \
+  "$@"

.github/workflows/test-ubuntu.yml

@@ -1,6 +1,10 @@
+# Test on Ubuntu with various compiler and language standard versions.
 name: Test Ubuntu
 
-on:  [push, pull_request]
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
 
 jobs:
   build:
@@ -9,35 +13,59 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python: [python, python3]
+        python-version: ['3.14']
         cxx: [g++, clang++]
         std: [c++11, c++14, c++17]
         include:
-          # Add the appropriate docker image for each compiler.
-          # The images from teeks99/boost-python-test already have boost::python
-          # pre-reqs installed, see:
-          # https://github.com/teeks99/boost-python-test-docker
-          - cxx: clang++
-            docker-img: teeks99/boost-python-test:clang-21_1.89.0
-          - cxx: g++
-            docker-img: teeks99/boost-python-test:gcc-15_1.89.0
+          - python-version: '2.7'
+            cxx: g++
+            std: c++11
+          - python-version: '3.10'
+            cxx: g++
+            std: c++17
+          - python-version: '3.11'
+            cxx: g++
+            std: c++17
+          - python-version: '3.12'
+            cxx: g++
+            std: c++17
+          - python-version: '3.13'
+            cxx: g++
+            std: c++17
+          # Also test with free-threaded build of Python
+          - python-version: '3.14t'
+            cxx: clang++
+            std: c++17
 
     container:
-      image: ${{ matrix.docker-img }}
+      # Add the appropriate docker image for the compiler.
+      # The images from teeks99/boost-python-test already have boost::python
+      # pre-reqs installed, see:
+      # https://github.com/teeks99/boost-python-test-docker
+      image: ${{ matrix.cxx == 'g++' &&
+        'teeks99/boost-python-test:gcc-15_1.89.0' ||
+        'teeks99/boost-python-test:clang-21_1.89.0' }}
 
     steps:
     - uses: actions/checkout@v5
-
+    - name: setup python
+      if: "${{ matrix.python-version  != '2.7' }}"
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
     - name: setup prerequisites
       run: |
         # Warning: this is not necessarily the same Python version as the one configured above !
         python3 -m pip install -U faber --break-system-packages
-    - name: build
+        echo "CXX=${{ matrix.cxx }}" >> "$GITHUB_ENV"
+        echo "CXX_STD=${{ matrix.std }}" >> "$GITHUB_ENV"
+    - name: build-py2
+      if: "${{ matrix.python-version  == '2.7' }}"
       run: |
-        ${{ matrix.python }} --version
+        python --version
         ${{ matrix.cxx }} --version
         faber -v
-        sed -e "s/\$PYTHON/${{ matrix.python }}/g" .ci/faber > ~/.faber
+        sed -e "s/\$PYTHON/python/g" .ci/faber > ~/.faber
         faber \
           --with-boost-include=${BOOST_PY_DEPS} \
           --builddir=build \
@@ -45,7 +73,12 @@ jobs:
           cxxflags=-std=${{ matrix.std }} \
           cppflags=-std=${{ matrix.std }} \
           -j`nproc`
-    - name: test
+    - name: build-py3
+      if: "${{ matrix.python-version  != '2.7' }}"
+      run: |
+        .github/run-faber.sh
+    - name: test-py2
+      if: "${{ matrix.python-version  == '2.7' }}"
       run: |
         faber \
           --with-boost-include=${BOOST_PY_DEPS} \
@@ -55,3 +88,7 @@ jobs:
           cppflags=-std=${{ matrix.std }} \
           -j`nproc` \
           test.report
+    - name: test-py3
+      if: "${{ matrix.python-version  != '2.7' }}"
+      run: |
+        .github/run-faber.sh test.report

include/boost/python/detail/pymutex.hpp

@@ -0,0 +1,103 @@
+// Copyright 2025 Boost.Python Contributors
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_PYTHON_DETAIL_PYMUTEX_HPP
+#define BOOST_PYTHON_DETAIL_PYMUTEX_HPP
+
+#include <boost/python/detail/prefix.hpp>
+#ifdef Py_GIL_DISABLED
+// needed for pymutex wrapper
+#include <atomic>
+#include <cstddef>
+#endif
+
+namespace boost { namespace python { namespace detail {
+
+#ifdef Py_GIL_DISABLED
+
+// Re-entrant wrapper around PyMutex for free-threaded Python
+// Similar to _PyRecursiveMutex or threading.RLock
+class pymutex {
+    PyMutex m_mutex;
+    std::atomic<unsigned long> m_owner;
+    std::size_t m_level;
+
+public:
+    pymutex() : m_mutex({}), m_owner(0), m_level(0) {}
+
+    // Non-copyable, non-movable
+    pymutex(const pymutex&) = delete;
+    pymutex& operator=(const pymutex&) = delete;
+
+    void lock() {
+        unsigned long thread = PyThread_get_thread_ident();
+        if (m_owner.load(std::memory_order_relaxed) == thread) {
+            m_level++;
+            return;
+        }
+        PyMutex_Lock(&m_mutex);
+        m_owner.store(thread, std::memory_order_relaxed);
+        // m_level should be 0 when we acquire the lock
+    }
+
+    void unlock() {
+        unsigned long thread = PyThread_get_thread_ident();
+        // Verify current thread owns the lock
+        if (m_owner.load(std::memory_order_relaxed) != thread) {
+            // This should never happen - programming error
+            return;
+        }
+        if (m_level > 0) {
+            m_level--;
+            return;
+        }
+        m_owner.store(0, std::memory_order_relaxed);
+        PyMutex_Unlock(&m_mutex);
+    }
+
+    bool is_locked_by_current_thread() const {
+        unsigned long thread = PyThread_get_thread_ident();
+        return m_owner.load(std::memory_order_relaxed) == thread;
+    }
+};
+
+
+// RAII lock guard for pymutex
+class pymutex_guard {
+    pymutex& m_mutex;
+
+public:
+    explicit pymutex_guard(pymutex& mutex) : m_mutex(mutex) {
+        m_mutex.lock();
+    }
+
+    ~pymutex_guard() {
+        m_mutex.unlock();
+    }
+
+    // Non-copyable, non-movable
+    pymutex_guard(const pymutex_guard&) = delete;
+    pymutex_guard& operator=(const pymutex_guard&) = delete;
+};
+
+// Global mutex for protecting all Boost.Python internal state
+// Similar to pybind11's internals.mutex
+BOOST_PYTHON_DECL pymutex& get_global_mutex();
+
+// Macro for acquiring the global lock
+// Similar to pybind11's PYBIND11_LOCK_INTERNALS
+#define BOOST_PYTHON_LOCK_STATE() \
+    ::boost::python::detail::pymutex_guard lock(::boost::python::detail::get_global_mutex())
+
+#else
+
+// No-op macro when not in free-threaded mode
+#define BOOST_PYTHON_LOCK_STATE()
+
+#endif // Py_GIL_DISABLED
+
+}}} // namespace boost::python::detail
+
+#endif // BOOST_PYTHON_DETAIL_PYMUTEX_HPP

include/boost/python/module_init.hpp

@@ -11,11 +11,41 @@
 
 # ifndef BOOST_PYTHON_MODULE_INIT
 
-namespace boost { namespace python { namespace detail {
+namespace boost { namespace python {
+
+#ifdef HAS_CXX11
+// Use to activate the Py_MOD_GIL_NOT_USED flag.
+class mod_gil_not_used {
+public:
+    explicit mod_gil_not_used(bool flag = true) : flag_(flag) {}
+    bool flag() const { return flag_; }
+
+private:
+    bool flag_;
+};
+
+namespace detail {
+
+inline bool gil_not_used_option() { return false; }
+template <typename F, typename... O>
+bool gil_not_used_option(F &&, O &&...o);
+template <typename... O>
+inline bool gil_not_used_option(mod_gil_not_used f, O &&...o) {
+    return f.flag() || gil_not_used_option(o...);
+}
+template <typename F, typename... O>
+inline bool gil_not_used_option(F &&, O &&...o) {
+    return gil_not_used_option(o...);
+}
+
+}
+#endif // HAS_CXX11
+
+namespace detail {
 
 #  if PY_VERSION_HEX >= 0x03000000
 
-BOOST_PYTHON_DECL PyObject* init_module(PyModuleDef&, void(*)());
+BOOST_PYTHON_DECL PyObject* init_module(PyModuleDef&, void(*)(), bool gil_not_used = false);
 
 #else
 
@@ -27,7 +57,37 @@ BOOST_PYTHON_DECL PyObject* init_module(char const* name, void(*)());
 
 #  if PY_VERSION_HEX >= 0x03000000
 
-#   define _BOOST_PYTHON_MODULE_INIT(name) \
+#   ifdef HAS_CXX11
+#    define _BOOST_PYTHON_MODULE_INIT(name, ...) \
+  PyObject* BOOST_PP_CAT(PyInit_, name)()  \
+  { \
+    static PyModuleDef_Base initial_m_base = { \
+        PyObject_HEAD_INIT(NULL) \
+        0, /* m_init */ \
+        0, /* m_index */ \
+        0 /* m_copy */ };  \
+    static PyMethodDef initial_methods[] = { { 0, 0, 0, 0 } }; \
+ \
+    static struct PyModuleDef moduledef = { \
+        initial_m_base, \
+        BOOST_PP_STRINGIZE(name), \
+        0, /* m_doc */ \
+        -1, /* m_size */ \
+        initial_methods, \
+        0,  /* m_reload */ \
+        0, /* m_traverse */ \
+        0, /* m_clear */ \
+        0,  /* m_free */ \
+    }; \
+ \
+    return boost::python::detail::init_module( \
+        moduledef, BOOST_PP_CAT(init_module_, name), \
+        boost::python::detail::gil_not_used_option(__VA_ARGS__) ); \
+  } \
+  void BOOST_PP_CAT(init_module_, name)()
+
+#   else // !HAS_CXX11
+#    define _BOOST_PYTHON_MODULE_INIT(name) \
   PyObject* BOOST_PP_CAT(PyInit_, name)()  \
   { \
     static PyModuleDef_Base initial_m_base = { \
@@ -53,6 +113,7 @@ BOOST_PYTHON_DECL PyObject* init_module(char const* name, void(*)());
         moduledef, BOOST_PP_CAT(init_module_, name) ); \
   } \
   void BOOST_PP_CAT(init_module_, name)()
+#   endif // HAS_CXX11
 
 #  else
 
@@ -66,9 +127,15 @@ BOOST_PYTHON_DECL PyObject* init_module(char const* name, void(*)());
 
 #  endif
 
-#  define BOOST_PYTHON_MODULE_INIT(name)                       \
+#  if defined(HAS_CXX11) && (PY_VERSION_HEX >= 0x03000000)
+#   define BOOST_PYTHON_MODULE_INIT(name, ...)                  \
+  void BOOST_PP_CAT(init_module_,name)();                      \
+extern "C" BOOST_SYMBOL_EXPORT _BOOST_PYTHON_MODULE_INIT(name, __VA_ARGS__)
+#  else
+#   define BOOST_PYTHON_MODULE_INIT(name)                       \
   void BOOST_PP_CAT(init_module_,name)();                      \
 extern "C" BOOST_SYMBOL_EXPORT _BOOST_PYTHON_MODULE_INIT(name)
+#  endif // HAS_CXX11 && Python 3
 
 # endif
 

include/boost/python/object_core.hpp

@@ -419,6 +419,16 @@ inline api::object_base& api::object_base::operator=(api::object_base const& rhs
 
 inline api::object_base::~object_base()
 {
+#ifdef Py_GIL_DISABLED
+    // This is a not very elegant fix for a problem that occurs with the
+    // free-threaded build of Python.  If this is called when the interpreter
+    // has already been finalized, the thread-state can be null.  Unlike the
+    // GIL-enabled build, Py_DECREF() requires a valid thread-state.  This
+    // causes a memory leak, rather than crash, which seems preferable.
+    if (PyThreadState_GetUnchecked() == NULL) {
+        return;
+    }
+#endif
     assert( Py_REFCNT(m_ptr) > 0 );
     Py_DECREF(m_ptr);
 }

src/converter/from_python.cpp

@@ -11,6 +11,7 @@
 
 #include <boost/python/handle.hpp>
 #include <boost/python/detail/raw_pyobject.hpp>
+#include <boost/python/detail/pymutex.hpp>
 #include <boost/python/cast.hpp>
 
 #include <vector>
@@ -145,6 +146,8 @@ namespace
 
   inline bool visit(rvalue_from_python_chain const* chain)
   {
+      BOOST_PYTHON_LOCK_STATE();
+
       visited_t::iterator const p = std::lower_bound(visited.begin(), visited.end(), chain);
       if (p != visited.end() && *p == chain)
           return false;
@@ -160,6 +163,8 @@ namespace
 
       ~unvisit()
       {
+          BOOST_PYTHON_LOCK_STATE();
+
           visited_t::iterator const p = std::lower_bound(visited.begin(), visited.end(), chain);
           assert(p != visited.end());
           visited.erase(p);

src/converter/registry.cpp

@@ -5,6 +5,7 @@
 #include <boost/python/converter/registry.hpp>
 #include <boost/python/converter/registrations.hpp>
 #include <boost/python/converter/builtin_converters.hpp>
+#include <boost/python/detail/pymutex.hpp>
 
 #include <set>
 #include <stdexcept>
@@ -181,6 +182,8 @@ namespace // <unnamed>
 
   entry* get(type_info type, bool is_shared_ptr = false)
   {
+      BOOST_PYTHON_LOCK_STATE();
+
 #  ifdef BOOST_PYTHON_TRACE_REGISTRY
       registry_t::iterator p = entries().find(entry(type));
       
@@ -293,6 +296,8 @@ namespace registry
 
   registration const* query(type_info type)
   {
+      BOOST_PYTHON_LOCK_STATE();
+
       registry_t::iterator p = entries().find(entry(type));
 #  ifdef BOOST_PYTHON_TRACE_REGISTRY
       std::cout << "querying " << type

src/converter/type_id.cpp

@@ -5,6 +5,7 @@
 
 #include <boost/python/type_id.hpp>
 #include <boost/python/detail/decorated_type_id.hpp>
+#include <boost/python/detail/pymutex.hpp>
 #include <utility>
 #include <vector>
 #include <algorithm>
@@ -92,6 +93,7 @@ namespace
 
 bool cxxabi_cxa_demangle_is_broken()
 {
+    BOOST_PYTHON_LOCK_STATE();
     static bool was_tested = false;
     static bool is_broken = false;
     if (!was_tested) {
@@ -109,6 +111,8 @@ namespace detail
 {
   BOOST_PYTHON_DECL char const* gcc_demangle(char const* mangled)
   {
+      BOOST_PYTHON_LOCK_STATE();
+
       typedef std::vector<
           std::pair<char const*, char const*>
       > mangling_map;

src/dict.cpp

@@ -68,8 +68,16 @@ object dict_base::get(object_cref k) const
 {
     if (check_exact(this))
     {
+#ifdef Py_GIL_DISABLED
+        PyObject* result;
+        if (PyDict_GetItemRef(this->ptr(),k.ptr(),&result) < 0) {
+            throw_error_already_set();
+        }
+        return object(detail::new_reference(result ? result : Py_None));
+#else
         PyObject* result = PyDict_GetItem(this->ptr(),k.ptr());
         return object(detail::borrowed_reference(result ? result : Py_None));
+#endif
     }
     else
     {

src/errors.cpp

@@ -10,9 +10,21 @@
 #include <boost/python/errors.hpp>
 #include <boost/cast.hpp>
 #include <boost/python/detail/exception_handler.hpp>
+#include <boost/python/detail/pymutex.hpp>
 
 namespace boost { namespace python {
 
+#ifdef Py_GIL_DISABLED
+namespace detail {
+    // Global mutex for protecting all Boost.Python internal state
+    pymutex& get_global_mutex()
+    {
+        static pymutex mutex;
+        return mutex;
+    }
+}
+#endif
+
 error_already_set::~error_already_set() {}
 
 // IMPORTANT: this function may only be called from within a catch block!
@@ -20,8 +32,13 @@ BOOST_PYTHON_DECL bool handle_exception_impl(function0<void> f)
 {
     try
     {
-        if (detail::exception_handler::chain)
-            return detail::exception_handler::chain->handle(f);
+        detail::exception_handler* handler_chain = nullptr;
+        {
+            BOOST_PYTHON_LOCK_STATE();
+            handler_chain = detail::exception_handler::chain;
+        }
+        if (handler_chain)
+            return handler_chain->handle(f);
         f();
         return false;
     }
@@ -80,6 +97,7 @@ exception_handler::exception_handler(handler_function const& impl)
     : m_impl(impl)
     , m_next(0)
 {
+    BOOST_PYTHON_LOCK_STATE();
     if (chain != 0)
         tail->m_next = this;
     else

src/module.cpp

@@ -38,10 +38,17 @@ BOOST_PYTHON_DECL void scope_setattr_doc(char const* name, object const& x, char
 
 #if PY_VERSION_HEX >= 0x03000000
 
-BOOST_PYTHON_DECL PyObject* init_module(PyModuleDef& moduledef, void(*init_function)())
+BOOST_PYTHON_DECL PyObject* init_module(PyModuleDef& moduledef,
+    void(*init_function)(), bool gil_not_used)
 {
+    PyObject *mod = PyModule_Create(&moduledef);
+#ifdef Py_GIL_DISABLED
+    if (mod != NULL && gil_not_used) {
+        PyUnstable_Module_SetGIL(mod, Py_MOD_GIL_NOT_USED);
+    }
+#endif
     return init_module_in_scope(
-        PyModule_Create(&moduledef),
+        mod,
         init_function);
 }
 

src/object/function_doc_signature.cpp

@@ -135,7 +135,15 @@ namespace boost { namespace python { namespace objects {
             str name(get_qualname(py_type));
             if ( py_type->tp_flags & Py_TPFLAGS_HEAPTYPE ) {
                 // Qualify the type name if it is defined in a different module.
-                PyObject *type_module_name = PyDict_GetItemString(py_type->tp_dict, "__module__");
+                PyObject *type_module_name;
+#if PY_VERSION_HEX >= 0x030D0000
+                if (PyDict_GetItemStringRef(py_type->tp_dict, "__module__", &type_module_name) < 0) {
+                    throw_error_already_set();
+                }
+#else
+                type_module_name = PyDict_GetItemString(py_type->tp_dict, "__module__");
+                Py_XINCREF(type_module_name);
+#endif
                 if (
                     type_module_name
                     && PyObject_RichCompareBool(
@@ -144,8 +152,11 @@ namespace boost { namespace python { namespace objects {
                         Py_NE
                     ) != 0
                 ) {
-                    return str("%s.%s" % make_tuple(handle<>(borrowed(type_module_name)), name));
+                    str result = str("%s.%s" % make_tuple(handle<>(type_module_name), name));
+                    return result;
                 }
+                // Clean up the strong reference if we didn't use it
+                Py_XDECREF(type_module_name);
             }
             return name;
         } else {

src/object/inheritance.cpp

@@ -4,6 +4,7 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 #include <boost/python/object/inheritance.hpp>
 #include <boost/python/type_id.hpp>
+#include <boost/python/detail/pymutex.hpp>
 #include <boost/graph/breadth_first_search.hpp>
 #if _MSC_FULL_VER >= 13102171 && _MSC_FULL_VER <= 13102179
 # include <boost/graph/reverse_graph.hpp>
@@ -390,6 +391,8 @@ namespace
 
   inline void* convert_type(void* const p, class_id src_t, class_id dst_t, bool polymorphic)
   {
+      BOOST_PYTHON_LOCK_STATE();
+
       // Quickly rule out unregistered types
       index_entry* src_p = seek_type(src_t);
       if (src_p == 0)
@@ -452,6 +455,8 @@ BOOST_PYTHON_DECL void* find_static_type(void* p, class_id src_t, class_id dst_t
 BOOST_PYTHON_DECL void add_cast(
     class_id src_t, class_id dst_t, cast_function cast, bool is_downcast)
 {
+    BOOST_PYTHON_LOCK_STATE();
+
     // adding an edge will invalidate any record of unreachability in
     // the cache.
     static std::size_t expected_cache_len = 0;
@@ -490,6 +495,7 @@ BOOST_PYTHON_DECL void add_cast(
 BOOST_PYTHON_DECL void register_dynamic_id_aux(
     class_id static_id, dynamic_id_function get_dynamic_id)
 {
+    BOOST_PYTHON_LOCK_STATE();
     tuples::get<kdynamic_id>(*demand_type(static_id)) = get_dynamic_id;
 }
 

src/wrapper.cpp

@@ -21,7 +21,7 @@ namespace detail
                           this->m_self, const_cast<char*>(name))))
           )
           {
-              PyObject* borrowed_f = 0;
+              PyObject* class_f = 0;
 
               if (
                   PyMethod_Check(m.get())
@@ -29,12 +29,20 @@ namespace detail
                   && class_object->tp_dict != 0
               )
               {
-                  borrowed_f = ::PyDict_GetItemString(
+#if PY_VERSION_HEX >= 0x030D0000
+                  if (::PyDict_GetItemStringRef(
+                      class_object->tp_dict, const_cast<char*>(name), &class_f) < 0) {
+                      throw_error_already_set();
+                  }
+#else
+                  class_f = ::PyDict_GetItemString(
                       class_object->tp_dict, const_cast<char*>(name));
-
-
+                  Py_XINCREF(class_f);
+#endif
               }
-              if (borrowed_f != PyMethod_GET_FUNCTION(m.get()))
+              bool is_override = (class_f != PyMethod_GET_FUNCTION(m.get()));
+              Py_XDECREF(class_f);
+              if (is_override)
                   return override(m);
           }
       }

test/fabscript

@@ -68,6 +68,7 @@ for t in [('injected',),
           ('raw_ctor',),
           ('exception_translator',),
           ('module_init_exception',),
+          ('module_nogil',),
           ('test_enum', ['enum_ext']),
           ('test_cltree', ['cltree']),
           ('newtest', ['m1', 'm2']),

test/module_nogil.cpp

@@ -0,0 +1,25 @@
+// Test for BOOST_PYTHON_MODULE with optional mod_gil_not_used argument
+
+#include <boost/python/module.hpp>
+#include <boost/python/def.hpp>
+
+// Simple function to export
+int get_value() {
+    return 1234;
+}
+
+#if defined(HAS_CXX11) && (PY_VERSION_HEX >= 0x03000000)
+// C++11 build with Python 3: test with mod_gil_not_used option
+BOOST_PYTHON_MODULE(module_nogil_ext, boost::python::mod_gil_not_used())
+{
+    using namespace boost::python;
+    def("get_value", get_value);
+}
+#else
+// C++98 build or Python 2: test without optional arguments
+BOOST_PYTHON_MODULE(module_nogil_ext)
+{
+    using namespace boost::python;
+    def("get_value", get_value);
+}
+#endif

test/module_nogil.py

@@ -0,0 +1,29 @@
+"""
+>>> from module_nogil_ext import *
+>>> get_value()
+1234
+>>> import sys, sysconfig
+>>> Py_GIL_DISABLED = bool(sysconfig.get_config_var('Py_GIL_DISABLED'))
+>>> if Py_GIL_DISABLED and sys._is_gil_enabled():
+...    print('GIL is enabled and should not be')
+... else:
+...    print('okay')
+okay
+"""
+
+from __future__ import print_function
+
+def run(args = None):
+    import sys
+    import doctest
+
+    if args is not None:
+        sys.argv = args
+    return doctest.testmod(sys.modules.get(__name__))
+
+if __name__ == '__main__':
+    print("running...")
+    import sys
+    status = run()[0]
+    if (status == 0): print("Done.")
+    sys.exit(status)