Merge branch 'master' into sh_merge_master

.github/workflows/ci_sh_def.yml.patch

@@ -1,5 +1,5 @@
---- ci.yml	2022-07-21 06:53:22.850154382 -0700
+--- ci.yml	2022-08-21 19:29:32.986391968 -0700
-+++ ci_sh_def.yml	2022-07-21 06:54:29.947056986 -0700
++++ ci_sh_def.yml	2022-08-21 19:31:47.618458226 -0700
 @@ -1,4 +1,16 @@
 -name: CI
 +# PLEASE KEEP THIS GROUP OF FILES IN SYNC AT ALL TIMES:
@@ -154,8 +154,8 @@
      - name: Configure C++11
        # LTO leads to many undefined reference like
        # `pybind11::detail::function_call::function_call(pybind11::detail::function_call&&)
--      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DDOWNLOAD_CATCH=ON -S . -B build
+-      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -S . -B build
-+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" -S . -B build
++      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=11 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" -S . -B build
  
      - name: Build C++11
        run: cmake --build build -j 2
@@ -163,8 +163,8 @@
        run: git clean -fdx
  
      - name: Configure C++14
--      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DDOWNLOAD_CATCH=ON -S . -B build2
+-      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -S . -B build2
-+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DDOWNLOAD_CATCH=O -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"  -S . -B build2
++      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=14 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" -S . -B build2
  
      - name: Build C++14
        run: cmake --build build2 -j 2
@@ -172,8 +172,8 @@
        run: git clean -fdx
  
      - name: Configure C++17
--      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DDOWNLOAD_CATCH=ON -S . -B build3
+-      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -S . -B build3
-+      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DDOWNLOAD_CATCH=O -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT"  -S . -B build3
++      run: cmake -G "MinGW Makefiles" -DCMAKE_CXX_STANDARD=17 -DCMAKE_VERBOSE_MAKEFILE=ON -DPYBIND11_WERROR=ON -DDOWNLOAD_CATCH=ON -DCMAKE_CXX_FLAGS="-DPYBIND11_USE_SMART_HOLDER_AS_DEFAULT" -S . -B build3
  
      - name: Build C++17
        run: cmake --build build3 -j 2

.pre-commit-config.yaml

@@ -12,6 +12,9 @@
 #
 # See https://github.com/pre-commit/pre-commit
 
+# third-party content
+exclude: ^tools/JoinPaths.cmake$
+
 repos:
 # Standard hooks
 - repo: https://github.com/pre-commit/pre-commit-hooks
@@ -93,7 +96,7 @@ repos:
 
 # Automatically remove noqa that are not used
 - repo: https://github.com/asottile/yesqa
-  rev: "v1.3.0"
+  rev: "v1.4.0"
   hooks:
   - id: yesqa
     additional_dependencies: &flake8_dependencies
@@ -102,7 +105,7 @@ repos:
 
 # Flake8 also supports pre-commit natively (same author)
 - repo: https://github.com/PyCQA/flake8
-  rev: "5.0.2"
+  rev: "5.0.4"
   hooks:
   - id: flake8
     exclude: ^(docs/.*|tools/.*|ubench/.*)$

CMakeLists.txt

@@ -205,6 +205,9 @@ else()
 endif()
 
 include("${CMAKE_CURRENT_SOURCE_DIR}/tools/pybind11Common.cmake")
+# https://github.com/jtojnar/cmake-snips/#concatenating-paths-when-building-pkg-config-files
+# TODO: cmake 3.20 adds the cmake_path() function, which obsoletes this snippet
+include("${CMAKE_CURRENT_SOURCE_DIR}/tools/JoinPaths.cmake")
 
 # Relative directory setting
 if(USE_PYTHON_INCLUDE_DIR AND DEFINED Python_INCLUDE_DIRS)
@@ -269,6 +272,16 @@ if(PYBIND11_INSTALL)
     NAMESPACE "pybind11::"
     DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
 
+  # pkg-config support
+  if(NOT prefix_for_pc_file)
+    set(prefix_for_pc_file "${CMAKE_INSTALL_PREFIX}")
+  endif()
+  join_paths(includedir_for_pc_file "\${prefix}" "${CMAKE_INSTALL_INCLUDEDIR}")
+  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/tools/pybind11.pc.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/pybind11.pc" @ONLY)
+  install(FILES "${CMAKE_CURRENT_BINARY_DIR}/pybind11.pc"
+          DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/pkgconfig/")
+
   # Uninstall target
   if(PYBIND11_MASTER_PROJECT)
     configure_file("${CMAKE_CURRENT_SOURCE_DIR}/tools/cmake_uninstall.cmake.in"

include/pybind11/detail/class.h

@@ -504,31 +504,6 @@ inline PyObject *make_object_base_type(PyTypeObject *metaclass) {
     return (PyObject *) heap_type;
 }
 
-/// dynamic_attr: Support for `d = instance.__dict__`.
-extern "C" inline PyObject *pybind11_get_dict(PyObject *self, void *) {
-    PyObject *&dict = *_PyObject_GetDictPtr(self);
-    if (!dict) {
-        dict = PyDict_New();
-    }
-    Py_XINCREF(dict);
-    return dict;
-}
-
-/// dynamic_attr: Support for `instance.__dict__ = dict()`.
-extern "C" inline int pybind11_set_dict(PyObject *self, PyObject *new_dict, void *) {
-    if (!PyDict_Check(new_dict)) {
-        PyErr_Format(PyExc_TypeError,
-                     "__dict__ must be set to a dictionary, not a '%.200s'",
-                     get_fully_qualified_tp_name(Py_TYPE(new_dict)).c_str());
-        return -1;
-    }
-    PyObject *&dict = *_PyObject_GetDictPtr(self);
-    Py_INCREF(new_dict);
-    Py_CLEAR(dict);
-    dict = new_dict;
-    return 0;
-}
-
 /// dynamic_attr: Allow the garbage collector to traverse the internal instance `__dict__`.
 extern "C" inline int pybind11_traverse(PyObject *self, visitproc visit, void *arg) {
     PyObject *&dict = *_PyObject_GetDictPtr(self);
@@ -560,9 +535,17 @@ inline void enable_dynamic_attributes(PyHeapTypeObject *heap_type) {
     type->tp_traverse = pybind11_traverse;
     type->tp_clear = pybind11_clear;
 
-    static PyGetSetDef getset[] = {
+    static PyGetSetDef getset[] = {{
-        {const_cast<char *>("__dict__"), pybind11_get_dict, pybind11_set_dict, nullptr, nullptr},
+#if PY_VERSION_HEX < 0x03070000
-        {nullptr, nullptr, nullptr, nullptr, nullptr}};
+                                       const_cast<char *>("__dict__"),
+#else
+                                       "__dict__",
+#endif
+                                       PyObject_GenericGetDict,
+                                       PyObject_GenericSetDict,
+                                       nullptr,
+                                       nullptr},
+                                   {nullptr, nullptr, nullptr, nullptr, nullptr}};
     type->tp_getset = getset;
 }
 

include/pybind11/embed.h

@@ -150,6 +150,8 @@ inline void initialize_interpreter(bool init_signal_handlers = true,
 #else
     PyConfig config;
     PyConfig_InitIsolatedConfig(&config);
+    config.isolated = 0;
+    config.use_environment = 1;
     config.install_signal_handlers = init_signal_handlers ? 1 : 0;
 
     PyStatus status = PyConfig_SetBytesArgv(&config, argc, const_cast<char *const *>(argv));

include/pybind11/stl.h

@@ -45,7 +45,7 @@ using forwarded_type = conditional_t<std::is_lvalue_reference<T>::value,
 /// Forwards a value U as rvalue or lvalue according to whether T is rvalue or lvalue; typically
 /// used for forwarding a container's elements.
 template <typename T, typename U>
-forwarded_type<T, U> forward_like(U &&u) {
+constexpr forwarded_type<T, U> forward_like(U &&u) {
     return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
 }
 
@@ -78,7 +78,7 @@ struct set_caster {
         pybind11::set s;
         for (auto &&value : src) {
             auto value_ = reinterpret_steal<object>(
-                key_conv::cast(forward_like<T>(value), policy, parent));
+                key_conv::cast(detail::forward_like<T>(value), policy, parent));
             if (!value_ || !s.add(std::move(value_))) {
                 return handle();
             }
@@ -122,9 +122,9 @@ struct map_caster {
         }
         for (auto &&kv : src) {
             auto key = reinterpret_steal<object>(
-                key_conv::cast(forward_like<T>(kv.first), policy_key, parent));
+                key_conv::cast(detail::forward_like<T>(kv.first), policy_key, parent));
             auto value = reinterpret_steal<object>(
-                value_conv::cast(forward_like<T>(kv.second), policy_value, parent));
+                value_conv::cast(detail::forward_like<T>(kv.second), policy_value, parent));
             if (!key || !value) {
                 return handle();
             }
@@ -178,7 +178,7 @@ public:
         ssize_t index = 0;
         for (auto &&value : src) {
             auto value_ = reinterpret_steal<object>(
-                value_conv::cast(forward_like<T>(value), policy, parent));
+                value_conv::cast(detail::forward_like<T>(value), policy, parent));
             if (!value_) {
                 return handle();
             }
@@ -242,7 +242,7 @@ public:
         ssize_t index = 0;
         for (auto &&value : src) {
             auto value_ = reinterpret_steal<object>(
-                value_conv::cast(forward_like<T>(value), policy, parent));
+                value_conv::cast(detail::forward_like<T>(value), policy, parent));
             if (!value_) {
                 return handle();
             }

noxfile.py

@@ -27,7 +27,7 @@ def lint(session: nox.Session) -> None:
     Lint the codebase (except for clang-format/tidy).
     """
     session.install("pre-commit")
-    session.run("pre-commit", "run", "-a")
+    session.run("pre-commit", "run", "-a", *session.posargs)
 
 
 @nox.session(python=PYTHON_VERSIONS)
@@ -58,7 +58,7 @@ def tests_packaging(session: nox.Session) -> None:
     """
 
     session.install("-r", "tests/requirements.txt", "--prefer-binary")
-    session.run("pytest", "tests/extra_python_package")
+    session.run("pytest", "tests/extra_python_package", *session.posargs)
 
 
 @nox.session(reuse_venv=True)

pybind11/__init__.py

@@ -6,11 +6,12 @@ if sys.version_info < (3, 6):
 
 
 from ._version import __version__, version_info
-from .commands import get_cmake_dir, get_include
+from .commands import get_cmake_dir, get_include, get_pkgconfig_dir
 
 __all__ = (
     "version_info",
     "__version__",
     "get_include",
     "get_cmake_dir",
+    "get_pkgconfig_dir",
 )

pybind11/__main__.py

@@ -4,7 +4,7 @@ import argparse
 import sys
 import sysconfig
 
-from .commands import get_cmake_dir, get_include
+from .commands import get_cmake_dir, get_include, get_pkgconfig_dir
 
 
 def print_includes() -> None:
@@ -36,6 +36,11 @@ def main() -> None:
         action="store_true",
         help="Print the CMake module directory, ideal for setting -Dpybind11_ROOT in CMake.",
     )
+    parser.add_argument(
+        "--pkgconfigdir",
+        action="store_true",
+        help="Print the pkgconfig directory, ideal for setting $PKG_CONFIG_PATH.",
+    )
     args = parser.parse_args()
     if not sys.argv[1:]:
         parser.print_help()
@@ -43,6 +48,8 @@ def main() -> None:
         print_includes()
     if args.cmakedir:
         print(get_cmake_dir())
+    if args.pkgconfigdir:
+        print(get_pkgconfig_dir())
 
 
 if __name__ == "__main__":

pybind11/commands.py

@@ -23,3 +23,15 @@ def get_cmake_dir() -> str:
 
     msg = "pybind11 not installed, installation required to access the CMake files"
     raise ImportError(msg)
+
+
+def get_pkgconfig_dir() -> str:
+    """
+    Return the path to the pybind11 pkgconfig directory.
+    """
+    pkgconfig_installed_path = os.path.join(DIR, "share", "pkgconfig")
+    if os.path.exists(pkgconfig_installed_path):
+        return pkgconfig_installed_path
+
+    msg = "pybind11 not installed, installation required to access the pkgconfig files"
+    raise ImportError(msg)

setup.py

@@ -127,6 +127,7 @@ with remove_output("pybind11/include", "pybind11/share"):
             "-DCMAKE_INSTALL_PREFIX=pybind11",
             "-DBUILD_TESTING=OFF",
             "-DPYBIND11_NOPYTHON=ON",
+            "-Dprefix_for_pc_file=${pcfiledir}/../../",
         ]
         if "CMAKE_ARGS" in os.environ:
             fcommand = [

tests/extra_python_package/test_files.py

@@ -12,6 +12,16 @@ import zipfile
 DIR = os.path.abspath(os.path.dirname(__file__))
 MAIN_DIR = os.path.dirname(os.path.dirname(DIR))
 
+PKGCONFIG = """\
+prefix=${{pcfiledir}}/../../
+includedir=${{prefix}}/include
+
+Name: pybind11
+Description: Seamless operability between C++11 and Python
+Version: {VERSION}
+Cflags: -I${{includedir}}
+"""
+
 
 main_headers = {
     "include/pybind11/attr.h",
@@ -66,6 +76,10 @@ cmake_files = {
     "share/cmake/pybind11/pybind11Tools.cmake",
 }
 
+pkgconfig_files = {
+    "share/pkgconfig/pybind11.pc",
+}
+
 py_files = {
     "__init__.py",
     "__main__.py",
@@ -76,7 +90,7 @@ py_files = {
 }
 
 headers = main_headers | detail_headers | stl_headers
-src_files = headers | cmake_files
+src_files = headers | cmake_files | pkgconfig_files
 all_files = src_files | py_files
 
 
@@ -89,6 +103,7 @@ sdist_files = {
     "pybind11/share",
     "pybind11/share/cmake",
     "pybind11/share/cmake/pybind11",
+    "pybind11/share/pkgconfig",
     "pyproject.toml",
     "setup.cfg",
     "setup.py",
@@ -109,22 +124,25 @@ local_sdist_files = {
 }
 
 
+def read_tz_file(tar: tarfile.TarFile, name: str) -> bytes:
+    start = tar.getnames()[0] + "/"
+    inner_file = tar.extractfile(tar.getmember(f"{start}{name}"))
+    assert inner_file
+    with contextlib.closing(inner_file) as f:
+        return f.read()
+
+
+def normalize_line_endings(value: bytes) -> bytes:
+    return value.replace(os.linesep.encode("utf-8"), b"\n")
+
+
 def test_build_sdist(monkeypatch, tmpdir):
 
     monkeypatch.chdir(MAIN_DIR)
 
-    out = subprocess.check_output(
+    subprocess.run(
-        [
+        [sys.executable, "-m", "build", "--sdist", f"--outdir={tmpdir}"], check=True
-            sys.executable,
-            "-m",
-            "build",
-            "--sdist",
-            "--outdir",
-            str(tmpdir),
-        ]
     )
-    if hasattr(out, "decode"):
-        out = out.decode()
 
     (sdist,) = tmpdir.visit("*.tar.gz")
 
@@ -133,25 +151,17 @@ def test_build_sdist(monkeypatch, tmpdir):
         version = start[9:-1]
         simpler = {n.split("/", 1)[-1] for n in tar.getnames()[1:]}
 
-        with contextlib.closing(
+        setup_py = read_tz_file(tar, "setup.py")
-            tar.extractfile(tar.getmember(start + "setup.py"))
+        pyproject_toml = read_tz_file(tar, "pyproject.toml")
-        ) as f:
+        pkgconfig = read_tz_file(tar, "pybind11/share/pkgconfig/pybind11.pc")
-            setup_py = f.read()
+        cmake_cfg = read_tz_file(
+            tar, "pybind11/share/cmake/pybind11/pybind11Config.cmake"
+        )
 
-        with contextlib.closing(
+    assert (
-            tar.extractfile(tar.getmember(start + "pyproject.toml"))
+        'set(pybind11_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include")'
-        ) as f:
+        in cmake_cfg.decode("utf-8")
-            pyproject_toml = f.read()
+    )
-
-        with contextlib.closing(
-            tar.extractfile(
-                tar.getmember(
-                    start + "pybind11/share/cmake/pybind11/pybind11Config.cmake"
-                )
-            )
-        ) as f:
-            contents = f.read().decode("utf8")
-        assert 'set(pybind11_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include")' in contents
 
     files = {f"pybind11/{n}" for n in all_files}
     files |= sdist_files
@@ -162,9 +172,9 @@ def test_build_sdist(monkeypatch, tmpdir):
 
     with open(os.path.join(MAIN_DIR, "tools", "setup_main.py.in"), "rb") as f:
         contents = (
-            string.Template(f.read().decode())
+            string.Template(f.read().decode("utf-8"))
             .substitute(version=version, extra_cmd="")
-            .encode()
+            .encode("utf-8")
         )
     assert setup_py == contents
 
@@ -172,25 +182,19 @@ def test_build_sdist(monkeypatch, tmpdir):
         contents = f.read()
     assert pyproject_toml == contents
 
+    simple_version = ".".join(version.split(".")[:3])
+    pkgconfig_expected = PKGCONFIG.format(VERSION=simple_version).encode("utf-8")
+    assert normalize_line_endings(pkgconfig) == pkgconfig_expected
+
 
 def test_build_global_dist(monkeypatch, tmpdir):
 
     monkeypatch.chdir(MAIN_DIR)
     monkeypatch.setenv("PYBIND11_GLOBAL_SDIST", "1")
-    out = subprocess.check_output(
+    subprocess.run(
-        [
+        [sys.executable, "-m", "build", "--sdist", "--outdir", str(tmpdir)], check=True
-            sys.executable,
-            "-m",
-            "build",
-            "--sdist",
-            "--outdir",
-            str(tmpdir),
-        ]
     )
 
-    if hasattr(out, "decode"):
-        out = out.decode()
-
     (sdist,) = tmpdir.visit("*.tar.gz")
 
     with tarfile.open(str(sdist), "r:gz") as tar:
@@ -198,15 +202,17 @@ def test_build_global_dist(monkeypatch, tmpdir):
         version = start[16:-1]
         simpler = {n.split("/", 1)[-1] for n in tar.getnames()[1:]}
 
-        with contextlib.closing(
+        setup_py = read_tz_file(tar, "setup.py")
-            tar.extractfile(tar.getmember(start + "setup.py"))
+        pyproject_toml = read_tz_file(tar, "pyproject.toml")
-        ) as f:
+        pkgconfig = read_tz_file(tar, "pybind11/share/pkgconfig/pybind11.pc")
-            setup_py = f.read()
+        cmake_cfg = read_tz_file(
+            tar, "pybind11/share/cmake/pybind11/pybind11Config.cmake"
+        )
 
-        with contextlib.closing(
+    assert (
-            tar.extractfile(tar.getmember(start + "pyproject.toml"))
+        'set(pybind11_INCLUDE_DIR "${PACKAGE_PREFIX_DIR}/include")'
-        ) as f:
+        in cmake_cfg.decode("utf-8")
-            pyproject_toml = f.read()
+    )
 
     files = {f"pybind11/{n}" for n in all_files}
     files |= sdist_files
@@ -217,7 +223,7 @@ def test_build_global_dist(monkeypatch, tmpdir):
         contents = (
             string.Template(f.read().decode())
             .substitute(version=version, extra_cmd="")
-            .encode()
+            .encode("utf-8")
         )
         assert setup_py == contents
 
@@ -225,12 +231,16 @@ def test_build_global_dist(monkeypatch, tmpdir):
         contents = f.read()
         assert pyproject_toml == contents
 
+    simple_version = ".".join(version.split(".")[:3])
+    pkgconfig_expected = PKGCONFIG.format(VERSION=simple_version).encode("utf-8")
+    assert normalize_line_endings(pkgconfig) == pkgconfig_expected
+
 
 def tests_build_wheel(monkeypatch, tmpdir):
     monkeypatch.chdir(MAIN_DIR)
 
-    subprocess.check_output(
+    subprocess.run(
-        [sys.executable, "-m", "pip", "wheel", ".", "-w", str(tmpdir)]
+        [sys.executable, "-m", "pip", "wheel", ".", "-w", str(tmpdir)], check=True
     )
 
     (wheel,) = tmpdir.visit("*.whl")
@@ -257,8 +267,8 @@ def tests_build_global_wheel(monkeypatch, tmpdir):
     monkeypatch.chdir(MAIN_DIR)
     monkeypatch.setenv("PYBIND11_GLOBAL_SDIST", "1")
 
-    subprocess.check_output(
+    subprocess.run(
-        [sys.executable, "-m", "pip", "wheel", ".", "-w", str(tmpdir)]
+        [sys.executable, "-m", "pip", "wheel", ".", "-w", str(tmpdir)], check=True
     )
 
     (wheel,) = tmpdir.visit("*.whl")

tests/test_embed/catch.cpp

@@ -20,7 +20,25 @@
 namespace py = pybind11;
 
 int main(int argc, char *argv[]) {
+    // Setup for TEST_CASE in test_interpreter.cpp, tagging on a large random number:
+    std::string updated_pythonpath("pybind11_test_embed_PYTHONPATH_2099743835476552");
+    const char *preexisting_pythonpath = getenv("PYTHONPATH");
+    if (preexisting_pythonpath != nullptr) {
+#if defined(_WIN32)
+        updated_pythonpath += ';';
+#else
+        updated_pythonpath += ':';
+#endif
+        updated_pythonpath += preexisting_pythonpath;
+    }
+#if defined(_WIN32)
+    _putenv_s("PYTHONPATH", updated_pythonpath.c_str());
+#else
+    setenv("PYTHONPATH", updated_pythonpath.c_str(), /*replace=*/1);
+#endif
+
     py::scoped_interpreter guard{};
+
     auto result = Catch::Session().run(argc, argv);
 
     return result < 0xff ? result : 0xff;

tests/test_embed/test_interpreter.cpp

@@ -75,6 +75,13 @@ PYBIND11_EMBEDDED_MODULE(throw_error_already_set, ) {
     d["missing"].cast<py::object>();
 }
 
+TEST_CASE("PYTHONPATH is used to update sys.path") {
+    // The setup for this TEST_CASE is in catch.cpp!
+    auto sys_path = py::str(py::module_::import("sys").attr("path")).cast<std::string>();
+    REQUIRE_THAT(sys_path,
+                 Catch::Matchers::Contains("pybind11_test_embed_PYTHONPATH_2099743835476552"));
+}
+
 TEST_CASE("Pass classes and data between modules defined in C++ and Python") {
     auto module_ = py::module_::import("test_interpreter");
     REQUIRE(py::hasattr(module_, "DerivedWidget"));

tests/test_pytypes.cpp

@@ -109,6 +109,11 @@ TEST_SUBMODULE(pytypes, m) {
     m.def("get_iterator", [] { return py::iterator(); });
     // test_iterable
     m.def("get_iterable", [] { return py::iterable(); });
+    m.def("get_frozenset_from_iterable",
+          [](const py::iterable &iter) { return py::frozenset(iter); });
+    m.def("get_list_from_iterable", [](const py::iterable &iter) { return py::list(iter); });
+    m.def("get_set_from_iterable", [](const py::iterable &iter) { return py::set(iter); });
+    m.def("get_tuple_from_iterable", [](const py::iterable &iter) { return py::tuple(iter); });
     // test_float
     m.def("get_float", [] { return py::float_(0.0f); });
     // test_list

tests/test_pytypes.py

@@ -26,6 +26,22 @@ def test_iterator(doc):
     assert doc(m.get_iterator) == "get_iterator() -> Iterator"
 
 
+@pytest.mark.parametrize(
+    "pytype, from_iter_func",
+    [
+        (frozenset, m.get_frozenset_from_iterable),
+        (list, m.get_list_from_iterable),
+        (set, m.get_set_from_iterable),
+        (tuple, m.get_tuple_from_iterable),
+    ],
+)
+def test_from_iterable(pytype, from_iter_func):
+    my_iter = iter(range(10))
+    s = from_iter_func(my_iter)
+    assert type(s) == pytype
+    assert s == pytype(range(10))
+
+
 def test_iterable(doc):
     assert doc(m.get_iterable) == "get_iterable() -> Iterable"
 

tools/JoinPaths.cmake

@@ -0,0 +1,23 @@
+# This module provides function for joining paths
+# known from most languages
+#
+# SPDX-License-Identifier: (MIT OR CC0-1.0)
+# Copyright 2020 Jan Tojnar
+# https://github.com/jtojnar/cmake-snips
+#
+# Modelled after Python’s os.path.join
+# https://docs.python.org/3.7/library/os.path.html#os.path.join
+# Windows not supported
+function(join_paths joined_path first_path_segment)
+    set(temp_path "${first_path_segment}")
+    foreach(current_segment IN LISTS ARGN)
+        if(NOT ("${current_segment}" STREQUAL ""))
+            if(IS_ABSOLUTE "${current_segment}")
+                set(temp_path "${current_segment}")
+            else()
+                set(temp_path "${temp_path}/${current_segment}")
+            endif()
+        endif()
+    endforeach()
+    set(${joined_path} "${temp_path}" PARENT_SCOPE)
+endfunction()

tools/pybind11.pc.in

@@ -0,0 +1,7 @@
+prefix=@prefix_for_pc_file@
+includedir=@includedir_for_pc_file@
+
+Name: @PROJECT_NAME@
+Description: Seamless operability between C++11 and Python
+Version: @PROJECT_VERSION@
+Cflags: -I${includedir}

tools/pybind11NewTools.cmake

@@ -233,7 +233,9 @@ function(pybind11_add_module target_name)
     endif()
   endif()
 
-  if(NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
+  # Use case-insensitive comparison to match the result of $<CONFIG:cfgs>
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+  if(NOT MSVC AND NOT ${uppercase_CMAKE_BUILD_TYPE} MATCHES DEBUG|RELWITHDEBINFO)
     # Strip unnecessary sections of the binary on Linux/macOS
     pybind11_strip(${target_name})
   endif()

tools/pybind11Tools.cmake

@@ -115,6 +115,7 @@ if(PYTHON_IS_DEBUG)
     PROPERTY INTERFACE_COMPILE_DEFINITIONS Py_DEBUG)
 endif()
 
+# The <3.11 code here does not support release/debug builds at the same time, like on vcpkg
 if(CMAKE_VERSION VERSION_LESS 3.11)
   set_property(
     TARGET pybind11::module
@@ -130,16 +131,19 @@ if(CMAKE_VERSION VERSION_LESS 3.11)
     APPEND
     PROPERTY INTERFACE_LINK_LIBRARIES pybind11::pybind11 $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)
 else()
+  # The IMPORTED INTERFACE library here is to ensure that "debug" and "release" get processed outside
+  # of a generator expression - https://gitlab.kitware.com/cmake/cmake/-/issues/18424, as they are
+  # target_link_library keywords rather than real libraries.
+  add_library(pybind11::_ClassicPythonLibraries IMPORTED INTERFACE)
+  target_link_libraries(pybind11::_ClassicPythonLibraries INTERFACE ${PYTHON_LIBRARIES})
   target_link_libraries(
     pybind11::module
     INTERFACE
       pybind11::python_link_helper
-      "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>"
+      "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:pybind11::_ClassicPythonLibraries>")
-  )
 
   target_link_libraries(pybind11::embed INTERFACE pybind11::pybind11
-                                                  $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)
+                                                  pybind11::_ClassicPythonLibraries)
-
 endif()
 
 function(pybind11_extension name)
@@ -208,7 +212,9 @@ function(pybind11_add_module target_name)
     endif()
   endif()
 
-  if(NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
+  # Use case-insensitive comparison to match the result of $<CONFIG:cfgs>
+  string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
+  if(NOT MSVC AND NOT ${uppercase_CMAKE_BUILD_TYPE} MATCHES DEBUG|RELWITHDEBINFO)
     pybind11_strip(${target_name})
   endif()
 

tools/setup_global.py.in

@@ -29,6 +29,7 @@ main_headers = glob.glob("pybind11/include/pybind11/*.h")
 detail_headers = glob.glob("pybind11/include/pybind11/detail/*.h")
 stl_headers = glob.glob("pybind11/include/pybind11/stl/*.h")
 cmake_files = glob.glob("pybind11/share/cmake/pybind11/*.cmake")
+pkgconfig_files = glob.glob("pybind11/share/pkgconfig/*.pc")
 headers = main_headers + detail_headers + stl_headers
 
 cmdclass = {"install_headers": InstallHeadersNested}
@@ -51,6 +52,7 @@ setup(
     headers=headers,
     data_files=[
         (base + "share/cmake/pybind11", cmake_files),
+        (base + "share/pkgconfig", pkgconfig_files),
         (base + "include/pybind11", main_headers),
         (base + "include/pybind11/detail", detail_headers),
         (base + "include/pybind11/stl", stl_headers),

tools/setup_main.py.in

@@ -17,6 +17,7 @@ setup(
         "pybind11.include.pybind11.detail",
         "pybind11.include.pybind11.stl",
         "pybind11.share.cmake.pybind11",
+        "pybind11.share.pkgconfig",
     ],
     package_data={
         "pybind11": ["py.typed"],
@@ -24,6 +25,7 @@ setup(
         "pybind11.include.pybind11.detail": ["*.h"],
         "pybind11.include.pybind11.stl": ["*.h"],
         "pybind11.share.cmake.pybind11": ["*.cmake"],
+        "pybind11.share.pkgconfig": ["*.pc"],
     },
     extras_require={
         "global": ["pybind11_global==$version"]