fix: try using modern init for embedded interp

include/pybind11/embed.h

@@ -86,37 +86,6 @@ inline wchar_t *widen_chars(const char *safe_arg) {
     return widened_arg;
 }
 
-/// Python 2.x/3.x-compatible version of `PySys_SetArgv`
-inline void set_interpreter_argv(int argc, const char *const *argv, bool add_program_dir_to_path) {
-    // Before it was special-cased in python 3.8, passing an empty or null argv
-    // caused a segfault, so we have to reimplement the special case ourselves.
-    bool special_case = (argv == nullptr || argc <= 0);
-
-    const char *const empty_argv[]{"\0"};
-    const char *const *safe_argv = special_case ? empty_argv : argv;
-    if (special_case) {
-        argc = 1;
-    }
-
-    auto argv_size = static_cast<size_t>(argc);
-    // SetArgv* on python 3 takes wchar_t, so we have to convert.
-    std::unique_ptr<wchar_t *[]> widened_argv(new wchar_t *[argv_size]);
-    std::vector<std::unique_ptr<wchar_t[], wide_char_arg_deleter>> widened_argv_entries;
-    widened_argv_entries.reserve(argv_size);
-    for (size_t ii = 0; ii < argv_size; ++ii) {
-        widened_argv_entries.emplace_back(widen_chars(safe_argv[ii]));
-        if (!widened_argv_entries.back()) {
-            // A null here indicates a character-encoding failure or the python
-            // interpreter out of memory. Give up.
-            return;
-        }
-        widened_argv[ii] = widened_argv_entries.back().get();
-    }
-
-    auto *pysys_argv = widened_argv.get();
-    PySys_SetArgvEx(argc, pysys_argv, static_cast<int>(add_program_dir_to_path));
-}
-
 PYBIND11_NAMESPACE_END(detail)
 
 /** \rst
@@ -146,9 +115,54 @@ inline void initialize_interpreter(bool init_signal_handlers = true,
         pybind11_fail("The interpreter is already running");
     }
 
+#if PY_VERSION_HEX < 0x030B0000
+
     Py_InitializeEx(init_signal_handlers ? 1 : 0);
 
-    detail::set_interpreter_argv(argc, argv, add_program_dir_to_path);
+    // Before it was special-cased in python 3.8, passing an empty or null argv
+    // caused a segfault, so we have to reimplement the special case ourselves.
+    bool special_case = (argv == nullptr || argc <= 0);
+
+    const char *const empty_argv[]{"\0"};
+    const char *const *safe_argv = special_case ? empty_argv : argv;
+    if (special_case) {
+        argc = 1;
+    }
+
+    auto argv_size = static_cast<size_t>(argc);
+    // SetArgv* on python 3 takes wchar_t, so we have to convert.
+    std::unique_ptr<wchar_t *[]> widened_argv(new wchar_t *[argv_size]);
+    std::vector<std::unique_ptr<wchar_t[], wide_char_arg_deleter>> widened_argv_entries;
+    widened_argv_entries.reserve(argv_size);
+    for (size_t ii = 0; ii < argv_size; ++ii) {
+        widened_argv_entries.emplace_back(widen_chars(safe_argv[ii]));
+        if (!widened_argv_entries.back()) {
+            // A null here indicates a character-encoding failure or the python
+            // interpreter out of memory. Give up.
+            return;
+        }
+        widened_argv[ii] = widened_argv_entries.back().get();
+    }
+
+    auto *pysys_argv = widened_argv.get();
+
+    PySys_SetArgvEx(argc, pysys_argv, static_cast<int>(add_program_dir_to_path));
+#else
+    PyConfig config;
+    PyConfig_InitPythonConfig(&config);
+    config.safe_path = add_program_dir_to_path ? 0 : 1;
+    config.install_signal_handlers = init_signal_handlers ? 1 : 0;
+
+    PyStatus status = PyConfig_SetBytesArgv(&config, argc, const_cast<char *const *>(argv));
+    if (PyStatus_Exception(status)) {
+        // A failure here indicates a character-encoding failure or the python
+        // interpreter out of memory. Give up.
+        PyConfig_Clear(&config);
+        return;
+    }
+    Py_InitializeFromConfig(&config);
+    PyConfig_Clear(&config);
+#endif
 }
 
 /** \rst

tests/requirements.txt

@@ -1,4 +1,4 @@
-build==0.7.0
+build==0.8.0
 numpy==1.21.5; platform_python_implementation=="PyPy" and sys_platform=="linux" and python_version=="3.7"
 numpy==1.19.3; platform_python_implementation!="PyPy" and python_version=="3.6"
 numpy==1.21.5; platform_python_implementation!="PyPy" and python_version>="3.7" and python_version<"3.10"