dev-python/pygobject: Fix ImportWarnings with py3.10

Closes: https://bugs.gentoo.org/796929
Signed-off-by: Michał Górny <mgorny@gentoo.org>

dev-python/pygobject/files/pygobject-3.40.1-dynamicimporter-py310.patch

@@ -0,0 +1,63 @@
+From 1ae65be0f7e621002e2e29921e0252c1b57a170c Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <mgorny@gentoo.org>
+Date: Sun, 20 Jun 2021 17:54:52 +0200
+Subject: [PATCH] Implement PEP451 semantics for DynamicImporter
+
+Make DynamicImporter PEP451-compliant in order to silence ImportWarnings
+in Python 3.10.  This is mostly based on six._SixMetaPathImporter.
+
+Fixes #476
+---
+ gi/importer.py | 18 ++++++++++++++++++
+ 1 file changed, 18 insertions(+)
+
+diff --git a/gi/importer.py b/gi/importer.py
+index 32967974..006cf464 100644
+--- a/gi/importer.py
++++ b/gi/importer.py
+@@ -24,6 +24,7 @@
+ import sys
+ import warnings
+ import importlib
++import importlib.util
+ from contextlib import contextmanager
+ 
+ import gi
+@@ -103,6 +104,7 @@ def get_import_stacklevel(import_hook):
+ class DynamicImporter(object):
+ 
+     # Note: see PEP302 for the Importer Protocol implemented below.
++    # PEP451 for A ModuleSpec Type for the Import System.
+ 
+     def __init__(self, path):
+         self.path = path
+@@ -117,6 +119,16 @@ class DynamicImporter(object):
+ 
+         return self
+ 
++    def find_spec(self, fullname, path, target=None):
++        if not fullname.startswith(self.path):
++            return None
++
++        path, namespace = fullname.rsplit('.', 1)
++        if path != self.path:
++            return None
++
++        return importlib.util.spec_from_loader(fullname, self)
++
+     def load_module(self, fullname):
+         if fullname in sys.modules:
+             return sys.modules[fullname]
+@@ -149,3 +161,9 @@ class DynamicImporter(object):
+         sys.modules[fullname] = dynamic_module
+ 
+         return dynamic_module
++
++    def create_module(self, spec):
++        return self.load_module(spec.name)
++
++    def exec_module(self, module):
++        pass
+-- 
+2.32.0
+

dev-python/pygobject/pygobject-3.40.1-r1.ebuild

@@ -0,0 +1,78 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python3_{7..10} )
+
+inherit gnome.org meson python-r1 virtualx xdg
+
+DESCRIPTION="Python bindings for GObject Introspection"
+HOMEPAGE="https://pygobject.readthedocs.io/"
+
+LICENSE="LGPL-2.1+"
+SLOT="3"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~sparc-solaris ~x64-solaris ~x86-solaris"
+IUSE="+cairo examples test"
+RESTRICT="!test? ( test )"
+REQUIRED_USE="${PYTHON_REQUIRED_USE}"
+
+RDEPEND="${PYTHON_DEPS}
+	>=dev-libs/glib-2.56:2
+	>=dev-libs/gobject-introspection-1.56:=
+	dev-libs/libffi:=
+	cairo? (
+		>=dev-python/pycairo-1.16.0[${PYTHON_USEDEP}]
+		x11-libs/cairo[glib] )
+"
+DEPEND="${RDEPEND}
+	test? (
+		dev-libs/atk[introspection]
+		dev-python/pytest[${PYTHON_USEDEP}]
+		x11-libs/gdk-pixbuf:2[introspection,jpeg]
+		x11-libs/gtk+:3[introspection]
+		x11-libs/pango[introspection]
+	)
+"
+BDEPEND="
+	virtual/pkgconfig
+"
+
+PATCHES=(
+	"${FILESDIR}"/${P}-dynamicimporter-py310.patch
+)
+
+src_configure() {
+	configuring() {
+		meson_src_configure \
+			$(meson_feature cairo pycairo) \
+			$(meson_use test tests) \
+			-Dpython="${EPYTHON}"
+	}
+
+	python_foreach_impl configuring
+}
+
+src_compile() {
+	python_foreach_impl meson_src_compile
+}
+
+src_test() {
+	local -x GIO_USE_VFS="local" # prevents odd issues with deleting ${T}/.gvfs
+	local -x GIO_USE_VOLUME_MONITOR="unix" # prevent udisks-related failures in chroots, bug #449484
+
+	testing() {
+		local -x XDG_CACHE_HOME="${T}/${EPYTHON}"
+		meson_src_test || die "test failed for ${EPYTHON}"
+	}
+	virtx python_foreach_impl testing
+}
+
+src_install() {
+	installing() {
+		meson_src_install
+		python_optimize
+	}
+	python_foreach_impl installing
+	use examples && dodoc -r examples
+}