diff --git a/sdk_container/src/third_party/portage-stable/dev-python/cython/Manifest b/sdk_container/src/third_party/portage-stable/dev-python/cython/Manifest
index 04ea75d897..debd32e57d 100644
--- a/sdk_container/src/third_party/portage-stable/dev-python/cython/Manifest
+++ b/sdk_container/src/third_party/portage-stable/dev-python/cython/Manifest
@@ -1,3 +1,5 @@
 DIST cython-3.1.2.tar.gz 3184825 BLAKE2B 8be6016f3e9a5a7db71fd1cab65424db1a1cd8e9d0118f01432964eb816135021f77542aff2b1f0fd2af8f657f952ebce2f420d7610ae37c6c6956f94e54a636 SHA512 c674027dae58377ea71d8d8b15601e6e0c80435807603251e685608218805fef2e6eac4bbebd3c50c319cd7da660ff9ce1a6daeb673eb40ce70bbfe7f0069600
 DIST cython-3.1.3.tar.gz 3186689 BLAKE2B 520adbaf737b2625a5b6d5802484d84dccf12867ec4c6d379816b84c4413e9a766ee3c21f0ce4209f7961b19346f5e874ab09ed7bf9dc9a259afb8e65ae2359e SHA512 dbf14b486e9dc3cf978abd80f0fcc16d9ed8077d5a44c66b669291d6cc89beeae3e901e4975cee44208dcf52f11ba331a8d73587bf55891976a9ec4818a2470b
 DIST cython-3.1.4.tar.gz 3190778 BLAKE2B 7e554db21ba009dc70157ad03b414091f9bba15586c5fa842b23cc28c116dc153857e99c9981dd0f783f696b6afa3b2689424231b88ae89bcf9233fa8006b9c9 SHA512 dd524d7de59f949a8bac1cb944a7a2b4eb26b13107db4fd6f9af000d5af18dd08ac5768253721e3513f5b4c1593fdd8cf055f4ffc17d541b2b90ca461522e8f1
+DIST cython-3.1.5.tar.gz 3192050 BLAKE2B c076c14685cc0d01d3f70dd35c8dd6c8c6c285f0a7cd575b4b20d6b4ce941e8cc70e1859b4185e0bc485c6963e74e5b33fe9030ec9feb881cc8692434f497ae8 SHA512 cff0cebd3b72b47f92a0bb8f77e564655a966ee58442b7fe76db2263b8b0d5b3636bfb0a561b1f27fd10cfd113e52388b32971bea66f4d2cb6dbf8580465b873
+DIST cython-3.1.6.tar.gz 3192329 BLAKE2B 78ea2c33ce38441574c0566b2c093ed91c01b523812484a8da5f426c46d64d0e4c67c2b3e1bf8122c399a9c18372fe93ff63d20fcc2907e0a84c79fd1107d79d SHA512 29950bcb02b2000ffd278a881d91e9c99f554375238a1ea1e7866d6fff120233bca8d7a7c05de93136fddacdb4c071652de8c3b63b6c312dff43435193fe7b89
diff --git a/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.4.ebuild b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.4.ebuild
index df3f0a8288..a71d9d567a 100644
--- a/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.4.ebuild
+++ b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.4.ebuild
@@ -21,7 +21,7 @@ HOMEPAGE="
 
 LICENSE="Apache-2.0"
 SLOT="0"
-KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+KEYWORDS="~alpha amd64 arm arm64 ~hppa ~loong ~m68k ~mips ppc ppc64 ~riscv ~s390 ~sparc x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
 IUSE="test test-full"
 RESTRICT="!test? ( test )"
 
diff --git a/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.5.ebuild b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.5.ebuild
new file mode 100644
index 0000000000..df3f0a8288
--- /dev/null
+++ b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.5.ebuild
@@ -0,0 +1,128 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+DISTUTILS_EXT=1
+DISTUTILS_USE_PEP517=setuptools
+PYTHON_FULLY_TESTED=( python3_{11..14} )
+PYTHON_TESTED=( "${PYTHON_FULLY_TESTED[@]}" pypy3_11 )
+PYTHON_COMPAT=( "${PYTHON_TESTED[@]}" python3_{13,14}t )
+PYTHON_REQ_USE="threads(+)"
+
+inherit distutils-r1 multiprocessing pypi toolchain-funcs
+
+DESCRIPTION="A Python to C compiler"
+HOMEPAGE="
+	https://cython.org/
+	https://github.com/cython/cython/
+	https://pypi.org/project/Cython/
+"
+
+LICENSE="Apache-2.0"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+IUSE="test test-full"
+RESTRICT="!test? ( test )"
+
+BDEPEND="
+	${RDEPEND}
+	test? (
+		test-full? (
+			$(python_gen_cond_dep '
+				dev-python/numpy[${PYTHON_USEDEP}]
+			' "${PYTHON_FULLY_TESTED[@]}")
+		)
+	)
+"
+
+PATCHES=(
+	"${FILESDIR}/${PN}-0.29.23-pythran-parallel-install.patch"
+)
+
+distutils_enable_sphinx docs \
+	dev-python/jinja2 \
+	dev-python/sphinx-issues \
+	dev-python/sphinx-tabs
+
+python_compile() {
+	# Python gets confused when it is in sys.path before build.
+	local -x PYTHONPATH=
+
+	if use elibc_musl ; then
+		# Workaround for bug #925318
+		local -x LDFLAGS="${LDFLAGS} -Wl,-z,stack-size=2097152"
+	fi
+
+	distutils-r1_python_compile
+}
+
+python_test() {
+	# PYTHON_TESTED controls whether we expect the testsuite to
+	# pass at all, while PYTHON_FULLY_TESTED allows skipping before
+	# numpy is ported (and possibly other deps in future).
+	if ! has "${EPYTHON/./_}" "${PYTHON_TESTED[@]}"; then
+		einfo "Skipping tests on ${EPYTHON} (xfail)"
+		return
+	fi
+
+	# Needed to avoid confusing cache tests
+	unset CYTHON_FORCE_REGEN
+
+	tc-export CC
+
+	local testargs=(
+		-vv
+		-j "$(makeopts_jobs)"
+		--work-dir "${BUILD_DIR}"/tests
+
+		--no-examples
+		--no-code-style
+
+		# Fails to find embedded.c
+		--exclude 'embedded'
+		# coverage_installed_pkg needs dev-python/pip and doesn't like
+		# 'externally-managed' (bug #927995), but we don't really
+		# want automagic test dependencies at all, so just skip
+		# unimportant-for-us coverage tests entirely.
+		--exclude 'run.coverage*'
+		--exclude 'Cython.Coverage'
+		# Automagic on dev-python/python-tests, could add this in future
+		--exclude 'run.test_exceptions'
+		# TODO: Unpackaged dev-python/interpreters-pep-734 (interpreters_backport)
+		# This only shows up as a failure with >=3.13.
+		--exclude 'subinterpreters_threading_stress_test'
+
+		# The fix for https://github.com/cython/cython/issues/6938
+		# changes these tests s.t. they break with our build layout.
+		--exclude 'build.depfile*'
+	)
+
+	if [[ ${EPYTHON} == pypy3* ]] ; then
+		testargs+=(
+			# Recursion issue
+			--exclude 'run.if_else_expr'
+			--exclude 'run.test_patma*'
+			# Slight output difference (missing '<')
+			--exclude 'run.cpp_exception_ptr_just_handler'
+
+		)
+	fi
+
+	# Keep test-full for numpy as it's large and doesn't pass tests itself
+	# on niche arches.
+	if ! use test-full || ! has "${EPYTHON/./_}" "${PYTHON_FULLY_TESTED[@]}"; then
+		testargs+=(
+			--exclude 'run.numpy*'
+			--exclude 'run.ufunc'
+			--exclude 'numpy*'
+		)
+	fi
+
+	"${PYTHON}" runtests.py "${testargs[@]}" || die "Tests fail with ${EPYTHON}"
+}
+
+python_install_all() {
+	local DOCS=( CHANGES.rst README.rst ToDo.txt USAGE.txt )
+	distutils-r1_python_install_all
+}
diff --git a/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.6.ebuild b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.6.ebuild
new file mode 100644
index 0000000000..df3f0a8288
--- /dev/null
+++ b/sdk_container/src/third_party/portage-stable/dev-python/cython/cython-3.1.6.ebuild
@@ -0,0 +1,128 @@
+# Copyright 1999-2025 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+DISTUTILS_EXT=1
+DISTUTILS_USE_PEP517=setuptools
+PYTHON_FULLY_TESTED=( python3_{11..14} )
+PYTHON_TESTED=( "${PYTHON_FULLY_TESTED[@]}" pypy3_11 )
+PYTHON_COMPAT=( "${PYTHON_TESTED[@]}" python3_{13,14}t )
+PYTHON_REQ_USE="threads(+)"
+
+inherit distutils-r1 multiprocessing pypi toolchain-funcs
+
+DESCRIPTION="A Python to C compiler"
+HOMEPAGE="
+	https://cython.org/
+	https://github.com/cython/cython/
+	https://pypi.org/project/Cython/
+"
+
+LICENSE="Apache-2.0"
+SLOT="0"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~arm64-macos ~ppc-macos ~x64-macos ~x64-solaris"
+IUSE="test test-full"
+RESTRICT="!test? ( test )"
+
+BDEPEND="
+	${RDEPEND}
+	test? (
+		test-full? (
+			$(python_gen_cond_dep '
+				dev-python/numpy[${PYTHON_USEDEP}]
+			' "${PYTHON_FULLY_TESTED[@]}")
+		)
+	)
+"
+
+PATCHES=(
+	"${FILESDIR}/${PN}-0.29.23-pythran-parallel-install.patch"
+)
+
+distutils_enable_sphinx docs \
+	dev-python/jinja2 \
+	dev-python/sphinx-issues \
+	dev-python/sphinx-tabs
+
+python_compile() {
+	# Python gets confused when it is in sys.path before build.
+	local -x PYTHONPATH=
+
+	if use elibc_musl ; then
+		# Workaround for bug #925318
+		local -x LDFLAGS="${LDFLAGS} -Wl,-z,stack-size=2097152"
+	fi
+
+	distutils-r1_python_compile
+}
+
+python_test() {
+	# PYTHON_TESTED controls whether we expect the testsuite to
+	# pass at all, while PYTHON_FULLY_TESTED allows skipping before
+	# numpy is ported (and possibly other deps in future).
+	if ! has "${EPYTHON/./_}" "${PYTHON_TESTED[@]}"; then
+		einfo "Skipping tests on ${EPYTHON} (xfail)"
+		return
+	fi
+
+	# Needed to avoid confusing cache tests
+	unset CYTHON_FORCE_REGEN
+
+	tc-export CC
+
+	local testargs=(
+		-vv
+		-j "$(makeopts_jobs)"
+		--work-dir "${BUILD_DIR}"/tests
+
+		--no-examples
+		--no-code-style
+
+		# Fails to find embedded.c
+		--exclude 'embedded'
+		# coverage_installed_pkg needs dev-python/pip and doesn't like
+		# 'externally-managed' (bug #927995), but we don't really
+		# want automagic test dependencies at all, so just skip
+		# unimportant-for-us coverage tests entirely.
+		--exclude 'run.coverage*'
+		--exclude 'Cython.Coverage'
+		# Automagic on dev-python/python-tests, could add this in future
+		--exclude 'run.test_exceptions'
+		# TODO: Unpackaged dev-python/interpreters-pep-734 (interpreters_backport)
+		# This only shows up as a failure with >=3.13.
+		--exclude 'subinterpreters_threading_stress_test'
+
+		# The fix for https://github.com/cython/cython/issues/6938
+		# changes these tests s.t. they break with our build layout.
+		--exclude 'build.depfile*'
+	)
+
+	if [[ ${EPYTHON} == pypy3* ]] ; then
+		testargs+=(
+			# Recursion issue
+			--exclude 'run.if_else_expr'
+			--exclude 'run.test_patma*'
+			# Slight output difference (missing '<')
+			--exclude 'run.cpp_exception_ptr_just_handler'
+
+		)
+	fi
+
+	# Keep test-full for numpy as it's large and doesn't pass tests itself
+	# on niche arches.
+	if ! use test-full || ! has "${EPYTHON/./_}" "${PYTHON_FULLY_TESTED[@]}"; then
+		testargs+=(
+			--exclude 'run.numpy*'
+			--exclude 'run.ufunc'
+			--exclude 'numpy*'
+		)
+	fi
+
+	"${PYTHON}" runtests.py "${testargs[@]}" || die "Tests fail with ${EPYTHON}"
+}
+
+python_install_all() {
+	local DOCS=( CHANGES.rst README.rst ToDo.txt USAGE.txt )
+	distutils-r1_python_install_all
+}