diff --git a/eclass/distutils-r1.eclass b/eclass/distutils-r1.eclass
new file mode 100644
index 0000000..60f8147
--- /dev/null
+++ b/eclass/distutils-r1.eclass
@@ -0,0 +1,2073 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: distutils-r1.eclass
+# @MAINTAINER:
+# Python team <python@gentoo.org>
+# @AUTHOR:
+# Author: Michał Górny <mgorny@gentoo.org>
+# Based on the work of: Krzysztof Pawlik <nelchael@gentoo.org>
+# @SUPPORTED_EAPIS: 6 7 8
+# @PROVIDES: python-r1 python-single-r1
+# @BLURB: A simple eclass to build Python packages using distutils.
+# @DESCRIPTION:
+# A simple eclass providing functions to build Python packages using
+# the distutils build system. It exports phase functions for all
+# the src_* phases. Each of the phases runs two pseudo-phases:
+# python_..._all() (e.g. python_prepare_all()) once in ${S}, then
+# python_...() (e.g. python_prepare()) for each implementation
+# (see: python_foreach_impl() in python-r1).
+#
+# In distutils-r1_src_prepare(), the 'all' function is run before
+# per-implementation ones (because it creates the implementations),
+# per-implementation functions are run in a random order.
+#
+# In remaining phase functions, the per-implementation functions are run
+# before the 'all' one, and they are ordered from the least to the most
+# preferred implementation (so that 'better' files overwrite 'worse'
+# ones).
+#
+# If the ebuild doesn't specify a particular pseudo-phase function,
+# the default one will be used (distutils-r1_...). Defaults are provided
+# for all per-implementation pseudo-phases, python_prepare_all()
+# and python_install_all(); whenever writing your own pseudo-phase
+# functions, you should consider calling the defaults (and especially
+# distutils-r1_python_prepare_all).
+#
+# Please note that distutils-r1 sets RDEPEND and BDEPEND (or DEPEND
+# in earlier EAPIs) unconditionally for you.
+#
+# Also, please note that distutils-r1 will always inherit python-r1
+# as well. Thus, all the variables defined and documented there are
+# relevant to the packages using distutils-r1.
+#
+# For more information, please see the Python Guide:
+# https://projects.gentoo.org/python/guide/
+
+case "${EAPI:-0}" in
+	[0-5])
+		die "Unsupported EAPI=${EAPI:-0} (too old) for ${ECLASS}"
+		;;
+	[6-8])
+		;;
+	*)
+		die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
+		;;
+esac
+
+# @ECLASS_VARIABLE: DISTUTILS_OPTIONAL
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# If set to a non-null value, distutils part in the ebuild will
+# be considered optional. No dependencies will be added and no phase
+# functions will be exported.
+#
+# If you enable DISTUTILS_OPTIONAL, you have to set proper dependencies
+# for your package (using ${PYTHON_DEPS}) and to either call
+# distutils-r1 default phase functions or call the build system
+# manually.
+
+# @ECLASS_VARIABLE: DISTUTILS_SINGLE_IMPL
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# If set to a non-null value, the ebuild will support setting a single
+# Python implementation only. It will effectively replace the python-r1
+# eclass inherit with python-single-r1.
+#
+# Note that inheriting python-single-r1 will cause pkg_setup()
+# to be exported. It must be run in order for the eclass functions
+# to function properly.
+
+# @ECLASS_VARIABLE: DISTUTILS_USE_PEP517
+# @PRE_INHERIT
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# Enable the PEP 517 mode for the specified build system.  In this mode,
+# the complete build and install is done in python_compile(),
+# a venv-style install tree is provided to python_test(),
+# and python_install() just merges the temporary install tree
+# into the real fs.
+#
+# This mode is recommended for Python packages.  However, some packages
+# using custom hacks on top of distutils/setuptools may not install
+# correctly in this mode.  Please verify the list of installed files
+# when using it.
+#
+# The variable specifies the build system used.  Currently,
+# the following values are supported:
+#
+# - flit - flit_core backend
+#
+# - flit_scm - flit_scm backend
+#
+# - hatchling - hatchling backend (from hatch)
+#
+# - jupyter - jupyter_packaging backend
+#
+# - maturin - maturin backend
+#
+# - meson-python - meson-python (mesonpy) backend
+#
+# - no - no PEP517 build system (see below)
+#
+# - pbr - pbr backend
+#
+# - pdm - pdm.pep517 backend
+#
+# - poetry - poetry-core backend
+#
+# - setuptools - distutils or setuptools (incl. legacy mode)
+#
+# - sip - sipbuild backend
+#
+# - standalone - standalone build systems without external deps
+#   (used for bootstrapping).
+#
+# The variable needs to be set before the inherit line.  The eclass
+# adds appropriate build-time dependencies and verifies the value.
+#
+# The special value "no" indicates that the package has no build system.
+# This is not equivalent to unset DISTUTILS_USE_PEP517 (legacy mode).
+# It causes the eclass not to include any build system dependencies
+# and to disable default python_compile() and python_install()
+# implementations.  Baseline Python deps and phase functions will still
+# be set (depending on the value of DISTUTILS_OPTIONAL).  Most of
+# the other eclass functions will work.  Testing venv will be provided
+# in ${BUILD_DIR}/install after python_compile(), and if any (other)
+# files are found in ${BUILD_DIR}/install after python_install(), they
+# will be merged into ${D}.
+
+# @ECLASS_VARIABLE: DISTUTILS_USE_SETUPTOOLS
+# @DEFAULT_UNSET
+# @PRE_INHERIT
+# @DESCRIPTION:
+# Controls adding dev-python/setuptools dependency.  The allowed values
+# are:
+#
+# - no -- do not add the dependency (pure distutils package)
+#
+# - bdepend -- add it to BDEPEND (the default)
+#
+# - rdepend -- add it to BDEPEND+RDEPEND (e.g. when using pkg_resources)
+#
+# - pyproject.toml -- use pyproject2setuptools to install a project
+#   using pyproject.toml (flit, poetry...)
+#
+# - manual -- do not add the dependency and suppress the checks
+#   (assumes you will take care of doing it correctly)
+#
+# This variable is effective only if DISTUTILS_OPTIONAL is disabled.
+# It is available only in non-PEP517 mode.  It needs to be set before
+# the inherit line.
+
+# @ECLASS_VARIABLE: DISTUTILS_DEPS
+# @OUTPUT_VARIABLE
+# @DESCRIPTION:
+# This is an eclass-generated build-time dependency string for the build
+# system packages.  This string is automatically appended to BDEPEND
+# unless DISTUTILS_OPTIONAL is used.  This variable is available only
+# in PEP 517 mode.
+#
+# Example use:
+# @CODE
+# DISTUTILS_OPTIONAL=1
+# # ...
+# RDEPEND="${PYTHON_DEPS}"
+# BDEPEND="
+#     ${PYTHON_DEPS}
+#     ${DISTUTILS_DEPS}"
+# @CODE
+
+if [[ ! ${_DISTUTILS_R1} ]]; then
+
+[[ ${EAPI} == 6 ]] && inherit eutils xdg-utils
+inherit multibuild multiprocessing toolchain-funcs
+
+if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+	inherit python-r1
+else
+	inherit python-single-r1
+fi
+
+fi
+
+if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
+	EXPORT_FUNCTIONS src_prepare src_configure src_compile src_test src_install
+fi
+
+if [[ ! ${_DISTUTILS_R1} ]]; then
+
+_distutils_set_globals() {
+	local rdep bdep
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		if [[ ${DISTUTILS_USE_SETUPTOOLS} ]]; then
+			die "DISTUTILS_USE_SETUPTOOLS is not used in PEP517 mode"
+		fi
+
+		bdep='
+			>=dev-python/gpep517-8[${PYTHON_USEDEP}]
+		'
+		case ${DISTUTILS_USE_PEP517} in
+			flit)
+				bdep+='
+					>=dev-python/flit_core-3.7.1[${PYTHON_USEDEP}]
+				'
+				;;
+			flit_scm)
+				bdep+='
+					dev-python/flit_scm[${PYTHON_USEDEP}]
+				'
+				;;
+			hatchling)
+				bdep+='
+					>=dev-python/hatchling-1.3.1[${PYTHON_USEDEP}]
+				'
+				;;
+			jupyter)
+				bdep+='
+					>=dev-python/jupyter_packaging-0.12.0-r1[${PYTHON_USEDEP}]
+				'
+				;;
+			maturin)
+				bdep+='
+					>=dev-util/maturin-0.12.20[${PYTHON_USEDEP}]
+				'
+				;;
+			no)
+				# undo the generic deps added above
+				bdep=
+				;;
+			meson-python)
+				bdep+='
+					dev-python/meson-python[${PYTHON_USEDEP}]
+				'
+				;;
+			pbr)
+				bdep+='
+					>=dev-python/pbr-5.9.0[${PYTHON_USEDEP}]
+				'
+				;;
+			pdm)
+				bdep+='
+					>=dev-python/pdm-pep517-1.0.2[${PYTHON_USEDEP}]
+				'
+				;;
+			poetry)
+				bdep+='
+					>=dev-python/poetry-core-1.0.8[${PYTHON_USEDEP}]
+				'
+				;;
+			setuptools)
+				bdep+='
+					>=dev-python/setuptools-62.6.0[${PYTHON_USEDEP}]
+					dev-python/wheel[${PYTHON_USEDEP}]
+				'
+				;;
+			sip)
+				bdep+='
+					>=dev-python/sip-6.6.2[${PYTHON_USEDEP}]
+				'
+				;;
+			standalone)
+				;;
+			*)
+				die "Unknown DISTUTILS_USE_PEP517=${DISTUTILS_USE_PEP517}"
+				;;
+		esac
+	elif [[ ${DISTUTILS_OPTIONAL} ]]; then
+		if [[ ${DISTUTILS_USE_SETUPTOOLS} ]]; then
+			eqawarn "QA Notice: DISTUTILS_USE_SETUPTOOLS is not used when DISTUTILS_OPTIONAL"
+			eqawarn "is enabled."
+		fi
+	else
+		local setuptools_dep='>=dev-python/setuptools-42.0.2[${PYTHON_USEDEP}]'
+
+		case ${DISTUTILS_USE_SETUPTOOLS:-bdepend} in
+			no|manual)
+				;;
+			bdepend)
+				bdep+=" ${setuptools_dep}"
+				;;
+			rdepend)
+				bdep+=" ${setuptools_dep}"
+				rdep+=" ${setuptools_dep}"
+				;;
+			pyproject.toml)
+				bdep+=' >=dev-python/pyproject2setuppy-22[${PYTHON_USEDEP}]'
+				;;
+			*)
+				die "Invalid DISTUTILS_USE_SETUPTOOLS=${DISTUTILS_USE_SETUPTOOLS}"
+				;;
+		esac
+	fi
+
+	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+		bdep=${bdep//\$\{PYTHON_USEDEP\}/${PYTHON_USEDEP}}
+		rdep=${rdep//\$\{PYTHON_USEDEP\}/${PYTHON_USEDEP}}
+	else
+		[[ -n ${bdep} ]] && bdep="$(python_gen_cond_dep "${bdep}")"
+		[[ -n ${rdep} ]] && rdep="$(python_gen_cond_dep "${rdep}")"
+	fi
+
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		if [[ ${DISTUTILS_DEPS+1} ]]; then
+			if [[ ${DISTUTILS_DEPS} != "${bdep}" ]]; then
+				eerror "DISTUTILS_DEPS have changed between inherits!"
+				eerror "Before: ${DISTUTILS_DEPS}"
+				eerror "Now   : ${bdep}"
+				die "DISTUTILS_DEPS integrity check failed"
+			fi
+		else
+			DISTUTILS_DEPS=${bdep}
+			readonly DISTUTILS_DEPS
+		fi
+	fi
+
+	if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
+		RDEPEND="${PYTHON_DEPS} ${rdep}"
+		if [[ ${EAPI} != 6 ]]; then
+			BDEPEND="${PYTHON_DEPS} ${bdep}"
+		else
+			DEPEND="${PYTHON_DEPS} ${bdep}"
+		fi
+		REQUIRED_USE=${PYTHON_REQUIRED_USE}
+	fi
+}
+_distutils_set_globals
+unset -f _distutils_set_globals
+
+# @ECLASS_VARIABLE: PATCHES
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# An array containing patches to be applied to the sources before
+# copying them.
+#
+# If unset, no custom patches will be applied.
+#
+# Please note, however, that at some point the eclass may apply
+# additional distutils patches/quirks independently of this variable.
+#
+# Example:
+# @CODE
+# PATCHES=( "${FILESDIR}"/${P}-make-gentoo-happy.patch )
+# @CODE
+
+# @ECLASS_VARIABLE: DOCS
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# An array containing documents installed using dodoc. The files listed
+# there must exist in the directory from which
+# distutils-r1_python_install_all() is run (${S} by default).
+#
+# If unset, the function will instead look up files matching default
+# filename pattern list (from the Package Manager Specification),
+# and install those found.
+#
+# Example:
+# @CODE
+# DOCS=( NEWS README )
+# @CODE
+
+# @ECLASS_VARIABLE: HTML_DOCS
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# An array containing documents installed using dohtml. The files
+# and directories listed there must exist in the directory from which
+# distutils-r1_python_install_all() is run (${S} by default).
+#
+# If unset, no HTML docs will be installed.
+#
+# Example:
+# @CODE
+# HTML_DOCS=( doc/html/. )
+# @CODE
+
+# @ECLASS_VARIABLE: DISTUTILS_IN_SOURCE_BUILD
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# If set to a non-null value, in-source builds will be enabled.
+# If unset, the default is to use in-source builds when python_prepare()
+# is declared, and out-of-source builds otherwise.
+#
+# If in-source builds are used, the eclass will create a copy of package
+# sources for each Python implementation in python_prepare_all(),
+# and work on that copy afterwards.
+#
+# If out-of-source builds are used, the eclass will instead work
+# on the sources directly, prepending setup.py arguments with
+# 'build --build-base ${BUILD_DIR}' to enforce keeping & using built
+# files in the specific root.
+
+# @ECLASS_VARIABLE: DISTUTILS_ALL_SUBPHASE_IMPLS
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# An array of patterns specifying which implementations can be used
+# for *_all() sub-phase functions. If undefined, defaults to '*'
+# (allowing any implementation). If multiple values are specified,
+# implementations matching any of the patterns will be accepted.
+#
+# For the pattern syntax, please see _python_impl_matches
+# in python-utils-r1.eclass.
+#
+# If the restriction needs to apply conditionally to a USE flag,
+# the variable should be set conditionally as well (e.g. in an early
+# phase function or other convenient location).
+#
+# Please remember to add a matching || block to REQUIRED_USE,
+# to ensure that at least one implementation matching the patterns will
+# be enabled.
+#
+# Example:
+# @CODE
+# REQUIRED_USE="doc? ( || ( $(python_gen_useflags 'python2*') ) )"
+#
+# pkg_setup() {
+#     use doc && DISTUTILS_ALL_SUBPHASE_IMPLS=( 'python2*' )
+# }
+# @CODE
+
+# @ECLASS_VARIABLE: DISTUTILS_ARGS
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# An array containing options to be passed to the build system.
+# Supported by a subset of build systems used by the eclass.
+#
+# For setuptools, the arguments will be passed as first parameters
+# to setup.py invocations (via esetup.py), as well as to the PEP517
+# backend.  For future compatibility, only global options should be used
+# and specifying commands should be avoided.
+#
+# For sip, the options are passed to the PEP517 backend in a form
+# resembling sip-build calls.  Options taking arguments need to
+# be specified in the "--key=value" form, while flag options as "--key".
+# If an option takes multiple arguments, it can be specified multiple
+# times, same as for sip-build.
+#
+# Example:
+# @CODE
+# python_configure_all() {
+# 	DISTUTILS_ARGS=( --enable-my-hidden-option )
+# }
+# @CODE
+
+# @FUNCTION: distutils_enable_sphinx
+# @USAGE: <subdir> [--no-autodoc | <plugin-pkgs>...]
+# @DESCRIPTION:
+# Set up IUSE, BDEPEND, python_check_deps() and python_compile_all() for
+# building HTML docs via dev-python/sphinx.  python_compile_all() will
+# append to HTML_DOCS if docs are enabled.
+#
+# This helper is meant for the most common case, that is a single Sphinx
+# subdirectory with standard layout, building and installing HTML docs
+# behind USE=doc.  It assumes it's the only consumer of the three
+# aforementioned functions.  If you need to use a custom implemention,
+# you can't use it.
+#
+# If your package uses additional Sphinx plugins, they should be passed
+# (without PYTHON_USEDEP) as <plugin-pkgs>.  The function will take care
+# of setting appropriate any-of dep and python_check_deps().
+#
+# If no plugin packages are specified, the eclass will still utilize
+# any-r1 API to support autodoc (documenting source code).
+# If the package uses neither autodoc nor additional plugins, you should
+# pass --no-autodoc to disable this API and simplify the resulting code.
+#
+# This function must be called in global scope.  Take care not to
+# overwrite the variables set by it.  If you need to extend
+# python_compile_all(), you can call the original implementation
+# as sphinx_compile_all.
+distutils_enable_sphinx() {
+	debug-print-function ${FUNCNAME} "${@}"
+	[[ ${#} -ge 1 ]] || die "${FUNCNAME} takes at least one arg: <subdir>"
+
+	_DISTUTILS_SPHINX_SUBDIR=${1}
+	shift
+	_DISTUTILS_SPHINX_PLUGINS=( "${@}" )
+
+	local deps autodoc=1 d
+	deps=">=dev-python/sphinx-4.5.0-r1[\${PYTHON_USEDEP}]"
+	for d; do
+		if [[ ${d} == --no-autodoc ]]; then
+			autodoc=
+		else
+			deps+="
+				${d}[\${PYTHON_USEDEP}]"
+			if [[ ! ${autodoc} ]]; then
+				die "${FUNCNAME}: do not pass --no-autodoc if external plugins are used"
+			fi
+		fi
+	done
+
+	if [[ ${autodoc} ]]; then
+		if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
+			deps="$(python_gen_cond_dep "${deps}")"
+		else
+			deps="$(python_gen_any_dep "${deps}")"
+		fi
+
+		python_check_deps() {
+			use doc || return 0
+
+			local p
+			for p in ">=dev-python/sphinx-4.5.0-r1" \
+				"${_DISTUTILS_SPHINX_PLUGINS[@]}"
+			do
+				python_has_version "${p}[${PYTHON_USEDEP}]" ||
+					return 1
+			done
+		}
+	else
+		deps=">=dev-python/sphinx-4.5.0-r1"
+	fi
+
+	sphinx_compile_all() {
+		use doc || return
+
+		local confpy=${_DISTUTILS_SPHINX_SUBDIR}/conf.py
+		[[ -f ${confpy} ]] ||
+			die "${confpy} not found, distutils_enable_sphinx call wrong"
+
+		if [[ ${_DISTUTILS_SPHINX_PLUGINS[0]} == --no-autodoc ]]; then
+			if grep -F -q 'sphinx.ext.autodoc' "${confpy}"; then
+				die "distutils_enable_sphinx: --no-autodoc passed but sphinx.ext.autodoc found in ${confpy}"
+			fi
+		elif [[ -z ${_DISTUTILS_SPHINX_PLUGINS[@]} ]]; then
+			if ! grep -F -q 'sphinx.ext.autodoc' "${confpy}"; then
+				die "distutils_enable_sphinx: sphinx.ext.autodoc not found in ${confpy}, pass --no-autodoc"
+			fi
+		fi
+
+		build_sphinx "${_DISTUTILS_SPHINX_SUBDIR}"
+	}
+	python_compile_all() { sphinx_compile_all; }
+
+	IUSE+=" doc"
+	if [[ ${EAPI} == 6 ]]; then
+		DEPEND+=" doc? ( ${deps} )"
+	else
+		BDEPEND+=" doc? ( ${deps} )"
+	fi
+
+	# we need to ensure successful return in case we're called last,
+	# otherwise Portage may wrongly assume sourcing failed
+	return 0
+}
+
+# @FUNCTION: distutils_enable_tests
+# @USAGE: [--install] <test-runner>
+# @DESCRIPTION:
+# Set up IUSE, RESTRICT, BDEPEND and python_test() for running tests
+# with the specified test runner.  Also copies the current value
+# of RDEPEND to test?-BDEPEND.  The test-runner argument must be one of:
+#
+# - nose: nosetests (dev-python/nose)
+#
+# - pytest: dev-python/pytest
+#
+# - setup.py: setup.py test (no deps included)
+#
+# - unittest: for built-in Python unittest module
+#
+# Additionally, if --install is passed as the first parameter,
+# 'distutils_install_for_testing --via-root' is called before running
+# the test suite.
+#
+# This function is meant as a helper for common use cases, and it only
+# takes care of basic setup.  You still need to list additional test
+# dependencies manually.  If you have uncommon use case, you should
+# not use it and instead enable tests manually.
+#
+# This function must be called in global scope, after RDEPEND has been
+# declared.  Take care not to overwrite the variables set by it.
+distutils_enable_tests() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	_DISTUTILS_TEST_INSTALL=
+	case ${1} in
+		--install)
+			if [[ ${DISTUTILS_USE_PEP517} ]]; then
+				die "${FUNCNAME} --install is not implemented in PEP517 mode"
+			fi
+			_DISTUTILS_TEST_INSTALL=1
+			shift
+			;;
+	esac
+
+	[[ ${#} -eq 1 ]] || die "${FUNCNAME} takes exactly one argument: test-runner"
+	local test_pkg
+	case ${1} in
+		nose)
+			test_pkg=">=dev-python/nose-1.3.7_p20211111_p1-r1"
+			;;
+		pytest)
+			test_pkg=">=dev-python/pytest-7.1.2"
+			;;
+		setup.py)
+			;;
+		unittest)
+			test_pkg="dev-python/unittest-or-fail"
+			;;
+		*)
+			die "${FUNCNAME}: unsupported argument: ${1}"
+	esac
+
+	_DISTUTILS_TEST_RUNNER=${1}
+	python_test() { distutils-r1_python_test; }
+
+	local test_deps=${RDEPEND}
+	if [[ -n ${test_pkg} ]]; then
+		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+			test_deps+=" ${test_pkg}[${PYTHON_USEDEP}]"
+		else
+			test_deps+=" $(python_gen_cond_dep "
+				${test_pkg}[\${PYTHON_USEDEP}]
+			")"
+		fi
+	fi
+	if [[ -n ${test_deps} ]]; then
+		IUSE+=" test"
+		RESTRICT+=" !test? ( test )"
+		if [[ ${EAPI} == 6 ]]; then
+			DEPEND+=" test? ( ${test_deps} )"
+		else
+			BDEPEND+=" test? ( ${test_deps} )"
+		fi
+	fi
+
+	# we need to ensure successful return in case we're called last,
+	# otherwise Portage may wrongly assume sourcing failed
+	return 0
+}
+
+# @FUNCTION: esetup.py
+# @USAGE: [<args>...]
+# @DESCRIPTION:
+# Run setup.py using currently selected Python interpreter
+# (if ${EPYTHON} is set; fallback 'python' otherwise).
+#
+# setup.py will be passed the following, in order:
+#
+# 1. ${DISTUTILS_ARGS[@]}
+#
+# 2. ${mydistutilsargs[@]} (deprecated)
+#
+# 3. additional arguments passed to the esetup.py function.
+#
+# Please note that setup.py will respect defaults (unless overridden
+# via command-line options) from setup.cfg that is created
+# in distutils-r1_python_compile and in distutils-r1_python_install.
+#
+# This command dies on failure.
+esetup.py() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	_python_check_EPYTHON
+
+	if [[ ${BUILD_DIR} && ! ${DISTUTILS_USE_PEP517} ]]; then
+		_distutils-r1_create_setup_cfg
+	fi
+
+	local setup_py=( setup.py )
+	if [[ ${DISTUTILS_USE_SETUPTOOLS} == pyproject.toml ]]; then
+		setup_py=( -m pyproject2setuppy )
+	elif [[ ! -f setup.py ]]; then
+		if [[ ! -f setup.cfg ]]; then
+			die "${FUNCNAME}: setup.py nor setup.cfg not found"
+		fi
+		setup_py=( -c "from setuptools import setup; setup()" )
+	fi
+
+	if [[ ${EAPI} != [67] && ${mydistutilsargs[@]} ]]; then
+		die "mydistutilsargs is banned in EAPI ${EAPI} (use DISTUTILS_ARGS)"
+	fi
+
+	set -- "${EPYTHON}" "${setup_py[@]}" "${DISTUTILS_ARGS[@]}" \
+		"${mydistutilsargs[@]}" "${@}"
+
+	echo "${@}" >&2
+	"${@}" || die -n
+	local ret=${?}
+
+	if [[ ${BUILD_DIR} && ! ${DISTUTILS_USE_PEP517} ]]; then
+		rm "${HOME}"/.pydistutils.cfg || die -n
+	fi
+
+	return ${ret}
+}
+
+# @FUNCTION: distutils_install_for_testing
+# @USAGE: [--via-root|--via-home|--via-venv] [<args>...]
+# @DESCRIPTION:
+# Install the package into a temporary location for running tests.
+# Update PYTHONPATH appropriately and set TEST_DIR to the test
+# installation root. The Python packages will be installed in 'lib'
+# subdir, and scripts in 'scripts' subdir (like in BUILD_DIR).
+#
+# Please note that this function should be only used if package uses
+# namespaces (and therefore proper install needs to be done to enforce
+# PYTHONPATH) or tests rely on the results of install command.
+# For most of the packages, tests built in BUILD_DIR are good enough.
+#
+# The function supports three install modes.  These are:
+#
+# --via-root (the default) that uses 'setup.py install --root=...'
+# combined with PYTHONPATH and is recommended for the majority
+# of packages.
+#
+# --via-venv that creates a (non-isolated) venv and installs the package
+# into it via 'setup.py install'.  This mode does not use PYTHONPATH
+# but requires python to be called via PATH.  It may solve a few corner
+# cases that --via-root do not support.
+#
+# --via-home that uses 'setup.py install --home=...'.  This is
+# a historical mode that was mostly broken by setuptools 50.3.0+.
+# If your package does not work with the other two modes but works with
+# this one, please report a bug.
+#
+# Please note that in order to test the solution properly you need
+# to unmerge the package first.
+#
+# This function is not available in PEP517 mode.  The eclass provides
+# a venv-style install unconditionally therefore, and therefore it
+# should no longer be necessary.
+distutils_install_for_testing() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	# A few notes about --via-home mode:
+	# 1) 'install --home' is terribly broken on pypy, so we need
+	#    to override --install-lib and --install-scripts,
+	# 2) non-root 'install' complains about PYTHONPATH and missing dirs,
+	#    so we need to set it properly and mkdir them,
+	# 3) it runs a bunch of commands which write random files to cwd,
+	#    in order to avoid that, we add the necessary path overrides
+	#    in _distutils-r1_create_setup_cfg.
+
+	local install_method=root
+	case ${1} in
+		--via-home)
+			[[ ${EAPI} == [67] ]] || die "${*} is banned in EAPI ${EAPI}"
+			install_method=home
+			shift
+			;;
+		--via-root)
+			install_method=root
+			shift
+			;;
+		--via-venv)
+			install_method=venv
+			shift
+			;;
+	esac
+
+	TEST_DIR=${BUILD_DIR}/test
+	local add_args=()
+
+	if [[ ${install_method} == venv ]]; then
+		# create a quasi-venv
+		mkdir -p "${TEST_DIR}"/bin || die
+		ln -s "${PYTHON}" "${TEST_DIR}/bin/${EPYTHON}" || die
+		ln -s "${EPYTHON}" "${TEST_DIR}/bin/python3" || die
+		ln -s "${EPYTHON}" "${TEST_DIR}/bin/python" || die
+		cat > "${TEST_DIR}"/pyvenv.cfg <<-EOF || die
+			include-system-site-packages = true
+		EOF
+
+		# we only do the minimal necessary subset of activate script
+		PATH=${TEST_DIR}/bin:${PATH}
+		# unset PYTHONPATH in order to prevent BUILD_DIR from overriding
+		# venv packages
+		unset PYTHONPATH
+
+		# force root-style install (note: venv adds TEST_DIR to prefixes,
+		# so we need to pass --root=/)
+		add_args=(
+			--root=/
+		)
+	else
+		local bindir=${TEST_DIR}/scripts
+		local libdir=${TEST_DIR}/lib
+		PATH=${bindir}:${PATH}
+		PYTHONPATH=${libdir}:${PYTHONPATH}
+
+		case ${install_method} in
+			home)
+				add_args=(
+					--home="${TEST_DIR}"
+					--install-lib="${libdir}"
+					--install-scripts="${bindir}"
+				)
+				mkdir -p "${libdir}" || die
+				;;
+			root)
+				add_args=(
+					--root="${TEST_DIR}"
+					--install-lib=lib
+					--install-scripts=scripts
+				)
+				;;
+		esac
+	fi
+
+	esetup.py install "${add_args[@]}" "${@}"
+}
+
+# @FUNCTION: distutils_write_namespace
+# @USAGE: <namespace>...
+# @DESCRIPTION:
+# Write the __init__.py file for the requested namespace into PEP517
+# install tree, in order to fix running tests when legacy namespace
+# packages are installed (dev-python/namespace-*).
+#
+# This function must only be used in python_test().  The created file
+# will automatically be removed upon leaving the test phase.
+distutils_write_namespace() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	if [[ ! ${DISTUTILS_USE_PEP517:-no} != no ]]; then
+		die "${FUNCNAME} is available only in PEP517 mode"
+	fi
+	if [[ ${EBUILD_PHASE} != test || ! ${BUILD_DIR} ]]; then
+		die "${FUNCNAME} should only be used in python_test"
+	fi
+
+	local namespace
+	for namespace; do
+		if [[ ${namespace} == *[./]* ]]; then
+			die "${FUNCNAME} does not support nested namespaces at the moment"
+		fi
+
+		local path=${BUILD_DIR}/install$(python_get_sitedir)/${namespace}/__init__.py
+		if [[ -f ${path} ]]; then
+			die "Requested namespace ${path} exists already!"
+		fi
+		cat > "${path}" <<-EOF || die
+			__path__ = __import__('pkgutil').extend_path(__path__, __name__)
+		EOF
+		_DISTUTILS_POST_PHASE_RM+=( "${path}" )
+	done
+}
+
+# @FUNCTION: _distutils-r1_disable_ez_setup
+# @INTERNAL
+# @DESCRIPTION:
+# Stub out ez_setup.py and distribute_setup.py to prevent packages
+# from trying to download a local copy of setuptools.
+_distutils-r1_disable_ez_setup() {
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	local stub="def use_setuptools(*args, **kwargs): pass"
+	if [[ -f ez_setup.py ]]; then
+		echo "${stub}" > ez_setup.py || die
+	fi
+	if [[ -f distribute_setup.py ]]; then
+		echo "${stub}" > distribute_setup.py || die
+	fi
+}
+
+# @FUNCTION: _distutils-r1_handle_pyproject_toml
+# @INTERNAL
+# @DESCRIPTION:
+# Verify whether DISTUTILS_USE_SETUPTOOLS is set correctly
+# for pyproject.toml build systems (in non-PEP517 mode).
+_distutils-r1_handle_pyproject_toml() {
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	[[ ${DISTUTILS_USE_SETUPTOOLS} == manual ]] && return
+
+	if [[ ! -f setup.py && -f pyproject.toml ]]; then
+		if [[ ${DISTUTILS_USE_SETUPTOOLS} != pyproject.toml ]]; then
+			eerror "No setup.py found but pyproject.toml is present.  Please migrate"
+			eerror "the package to use DISTUTILS_USE_PEP517. See:"
+			eerror "  https://projects.gentoo.org/python/guide/distutils.html"
+			die "No setup.py found and PEP517 mode not enabled"
+		fi
+	fi
+}
+
+# @FUNCTION: _distutils-r1_check_all_phase_mismatch
+# @INTERNAL
+# @DESCRIPTION:
+# Verify whether *_all phase impls is not called from from non-*_all
+# subphase.
+_distutils-r1_check_all_phase_mismatch() {
+	if has "python_${EBUILD_PHASE}" "${FUNCNAME[@]}"; then
+		eqawarn "QA Notice: distutils-r1_python_${EBUILD_PHASE}_all called"
+		eqawarn "from python_${EBUILD_PHASE}.  Did you mean to use"
+		eqawarn "python_${EBUILD_PHASE}_all()?"
+		[[ ${EAPI} != [67] ]] &&
+			die "distutils-r1_python_${EBUILD_PHASE}_all called from python_${EBUILD_PHASE}."
+	fi
+}
+
+# @FUNCTION: _distutils-r1_print_package_versions
+# @INTERNAL
+# @DESCRIPTION:
+# Print the version of the relevant build system packages to aid
+# debugging.
+_distutils-r1_print_package_versions() {
+	local packages=()
+
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		packages+=(
+			dev-python/gpep517
+			dev-python/installer
+		)
+		case ${DISTUTILS_USE_PEP517} in
+			flit)
+				packages+=(
+					dev-python/flit_core
+				)
+				;;
+			flit_scm)
+				packages+=(
+					dev-python/flit_core
+					dev-python/flit_scm
+					dev-python/setuptools_scm
+				)
+				;;
+			hatchling)
+				packages+=(
+					dev-python/hatchling
+				)
+				;;
+			jupyter)
+				packages+=(
+					dev-python/jupyter_packaging
+					dev-python/setuptools
+					dev-python/setuptools_scm
+					dev-python/wheel
+				)
+				;;
+			maturin)
+				packages+=(
+					dev-util/maturin
+				)
+				;;
+			no)
+				return
+				;;
+			meson-python)
+				packages+=(
+					dev-python/meson-python
+				)
+				;;
+			pbr)
+				packages+=(
+					dev-python/pbr
+					dev-python/setuptools
+					dev-python/wheel
+				)
+				;;
+			pdm)
+				packages+=(
+					dev-python/pdm-pep517
+					dev-python/setuptools
+				)
+				;;
+			poetry)
+				packages+=(
+					dev-python/poetry-core
+				)
+				;;
+			setuptools)
+				packages+=(
+					dev-python/setuptools
+					dev-python/setuptools_scm
+					dev-python/wheel
+				)
+				;;
+			sip)
+				packages+=(
+					dev-python/sip
+				)
+				;;
+		esac
+	else
+		case ${DISTUTILS_USE_SETUPTOOLS} in
+			manual|no)
+				return
+				;;
+			*)
+				packages+=(
+					dev-python/setuptools
+				)
+				;;
+		esac
+	fi
+
+	local pkg
+	einfo "Build system packages:"
+	for pkg in "${packages[@]}"; do
+		local installed=$(best_version "${pkg}")
+		einfo "  $(printf '%-30s' "${pkg}"): ${installed#${pkg}-}"
+	done
+}
+
+# @FUNCTION: distutils-r1_python_prepare_all
+# @DESCRIPTION:
+# The default python_prepare_all(). It applies the patches from PATCHES
+# array, then user patches and finally calls python_copy_sources to
+# create copies of resulting sources for each Python implementation.
+#
+# At some point in the future, it may also apply eclass-specific
+# distutils patches and/or quirks.
+distutils-r1_python_prepare_all() {
+	debug-print-function ${FUNCNAME} "${@}"
+	_distutils-r1_check_all_phase_mismatch
+
+	if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
+		default
+	fi
+
+	# by default, use in-source build if python_prepare() is used
+	if [[ ! ${DISTUTILS_IN_SOURCE_BUILD+1} ]]; then
+		if declare -f python_prepare >/dev/null; then
+			DISTUTILS_IN_SOURCE_BUILD=1
+		fi
+	fi
+
+	if [[ ! ${DISTUTILS_USE_PEP517} ]]; then
+		_distutils-r1_disable_ez_setup
+		_distutils-r1_handle_pyproject_toml
+
+		case ${DISTUTILS_USE_SETUPTOOLS} in
+			no)
+				eqawarn "Non-PEP517 builds are deprecated for ebuilds using plain distutils."
+				eqawarn "Please migrate to DISTUTILS_USE_PEP517=setuptools."
+				eqawarn "Please see Python Guide for more details:"
+				eqawarn "  https://projects.gentoo.org/python/guide/distutils.html"
+				;;
+		esac
+	fi
+
+	if [[ ${DISTUTILS_IN_SOURCE_BUILD} && ! ${DISTUTILS_SINGLE_IMPL} ]]
+	then
+		# create source copies for each implementation
+		python_copy_sources
+	fi
+
+	python_export_utf8_locale
+	[[ ${EAPI} == 6 ]] && xdg_environment_reset # Bug 577704
+	_distutils-r1_print_package_versions
+
+	_DISTUTILS_DEFAULT_CALLED=1
+}
+
+# @FUNCTION: _distutils-r1_create_setup_cfg
+# @INTERNAL
+# @DESCRIPTION:
+# Create implementation-specific configuration file for distutils,
+# setting proper build-dir (and install-dir) paths.
+_distutils-r1_create_setup_cfg() {
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	cat > "${HOME}"/.pydistutils.cfg <<-_EOF_ || die
+		[build]
+		build_base = ${BUILD_DIR}
+
+		# using a single directory for them helps us export
+		# ${PYTHONPATH} and ebuilds find the sources independently
+		# of whether the package installs extensions or not
+		#
+		# note: due to some packages (wxpython) relying on separate
+		# platlib & purelib dirs, we do not set --build-lib (which
+		# can not be overridden with --build-*lib)
+		build_platlib = %(build_base)s/lib
+		build_purelib = %(build_base)s/lib
+
+		# make the ebuild writer lives easier
+		build_scripts = %(build_base)s/scripts
+
+		# this is needed by distutils_install_for_testing since
+		# setuptools like to create .egg files for install --home.
+		[bdist_egg]
+		dist_dir = ${BUILD_DIR}/dist
+
+		# avoid packing up eggs in a zip as it often breaks test suites
+		[options]
+		zip_safe = False
+	_EOF_
+
+	if [[ ${EBUILD_PHASE} == install ]]; then
+		# we can't refer to ${D} before src_install()
+		cat >> "${HOME}"/.pydistutils.cfg <<-_EOF_ || die
+
+			# installation paths -- allow calling extra install targets
+			# without the default 'install'
+			[install]
+			compile = True
+			optimize = 2
+			root = ${D%/}
+		_EOF_
+
+		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+			# this gets appended to [install]
+			cat >> "${HOME}"/.pydistutils.cfg <<-_EOF_ || die
+				install_scripts = $(python_get_scriptdir)
+			_EOF_
+		fi
+	fi
+}
+
+# @FUNCTION: _distutils-r1_copy_egg_info
+# @INTERNAL
+# @DESCRIPTION:
+# Copy egg-info files to the ${BUILD_DIR} (that's going to become
+# egg-base in esetup.py). This way, we respect whatever's in upstream
+# egg-info.
+_distutils-r1_copy_egg_info() {
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	mkdir -p "${BUILD_DIR}" || die
+	# stupid freebsd can't do 'cp -t ${BUILD_DIR} {} +'
+	find -name '*.egg-info' -type d -exec cp -R -p {} "${BUILD_DIR}"/ ';' || die
+}
+
+# @FUNCTION: _distutils-r1_backend_to_key
+# @USAGE: <backend>
+# @INTERNAL
+# @DESCRIPTION:
+# Print the DISTUTILS_USE_PEP517 value corresponding to the backend
+# passed as the only argument.
+_distutils-r1_backend_to_key() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local backend=${1}
+	case ${backend} in
+		flit_core.buildapi|flit.buildapi)
+			echo flit
+			;;
+		flit_scm:buildapi)
+			echo flit_scm
+			;;
+		hatchling.build)
+			echo hatchling
+			;;
+		jupyter_packaging.build_api)
+			echo jupyter
+			;;
+		maturin)
+			echo maturin
+			;;
+		mesonpy)
+			echo meson-python
+			;;
+		pbr.build)
+			echo pbr
+			;;
+		pdm.pep517.api)
+			echo pdm
+			;;
+		poetry.core.masonry.api|poetry.masonry.api)
+			echo poetry
+			;;
+		setuptools.build_meta|setuptools.build_meta:__legacy__)
+			echo setuptools
+			;;
+		sipbuild.api)
+			echo sip
+			;;
+		*)
+			die "Unknown backend: ${backend}"
+			;;
+	esac
+}
+
+# @FUNCTION: _distutils-r1_get_backend
+# @INTERNAL
+# @DESCRIPTION:
+# Read (or guess, in case of setuptools) the build-backend
+# for the package in the current directory.
+_distutils-r1_get_backend() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local build_backend legacy_fallback
+	if [[ -f pyproject.toml ]]; then
+		# if pyproject.toml exists, try getting the backend from it
+		# NB: this could fail if pyproject.toml doesn't list one
+		build_backend=$(gpep517 get-backend)
+	fi
+	if [[ -z ${build_backend} && ${DISTUTILS_USE_PEP517} == setuptools &&
+		-f setup.py ]]
+	then
+		# use the legacy setuptools backend as a fallback
+		build_backend=setuptools.build_meta:__legacy__
+		legacy_fallback=1
+	fi
+	if [[ -z ${build_backend} ]]; then
+		die "Unable to obtain build-backend from pyproject.toml"
+	fi
+
+	if [[ ${DISTUTILS_USE_PEP517} != standalone ]]; then
+		# verify whether DISTUTILS_USE_PEP517 was set correctly
+		local expected_value=$(_distutils-r1_backend_to_key "${build_backend}")
+		if [[ ${DISTUTILS_USE_PEP517} != ${expected_value} ]]; then
+			eerror "DISTUTILS_USE_PEP517 does not match pyproject.toml!"
+			eerror "    have: DISTUTILS_USE_PEP517=${DISTUTILS_USE_PEP517}"
+			eerror "expected: DISTUTILS_USE_PEP517=${expected_value}"
+			eerror "(backend: ${build_backend})"
+			die "DISTUTILS_USE_PEP517 value incorrect"
+		fi
+
+		# fix deprecated backends up
+		local new_backend=
+		case ${build_backend} in
+			flit.buildapi)
+				new_backend=flit_core.buildapi
+				;;
+			poetry.masonry.api)
+				new_backend=poetry.core.masonry.api
+				;;
+			setuptools.build_meta:__legacy__)
+				# this backend should only be used as implicit fallback
+				[[ ! ${legacy_fallback} ]] &&
+					new_backend=setuptools.build_meta
+				;;
+		esac
+
+		if [[ -n ${new_backend} ]]; then
+			if [[ ! -f ${T}/.distutils_deprecated_backend_warned ]]; then
+				eqawarn "${build_backend} backend is deprecated.  Please see:"
+				eqawarn "https://projects.gentoo.org/python/guide/distutils.html#deprecated-pep-517-backends"
+				eqawarn "The eclass will be using ${new_backend} instead."
+				> "${T}"/.distutils_deprecated_backend_warned || die
+			fi
+			build_backend=${new_backend}
+		fi
+	fi
+
+	echo "${build_backend}"
+}
+
+# @FUNCTION: distutils_wheel_install
+# @USAGE: <root> <wheel>
+# @DESCRIPTION:
+# Install the specified wheel into <root>.
+#
+# This function is intended for expert use only.
+distutils_wheel_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+	if [[ ${#} -ne 2 ]]; then
+		die "${FUNCNAME} takes exactly two arguments: <root> <wheel>"
+	fi
+	if [[ -z ${PYTHON} ]]; then
+		die "PYTHON unset, invalid call context"
+	fi
+
+	local root=${1}
+	local wheel=${2}
+
+	einfo "  Installing ${wheel##*/} to ${root}"
+	if has_version -b ">=dev-python/gpep517-9"; then
+		# TODO: inline when we dep on >=9
+		local cmd=(
+			gpep517 install-wheel
+				--destdir="${root}"
+				--interpreter="${PYTHON}"
+				--prefix="${EPREFIX}/usr"
+				--optimize=all
+				"${wheel}"
+		)
+	else
+		local cmd=(
+			gpep517 install-wheel
+				--destdir="${root}"
+				--interpreter="${PYTHON}"
+				--prefix="${EPREFIX}/usr"
+				"${wheel}"
+		)
+	fi
+	printf '%s\n' "${cmd[*]}"
+	"${cmd[@]}" || die "Wheel install failed"
+
+	# remove installed licenses
+	find "${root}$(python_get_sitedir)" -depth \
+		\( -path '*.dist-info/COPYING*' \
+		-o -path '*.dist-info/LICENSE*' \
+		-o -path '*.dist-info/license_files/*' \
+		-o -path '*.dist-info/license_files' \
+		\) -delete || die
+}
+
+# @FUNCTION: distutils_pep517_install
+# @USAGE: <root>
+# @DESCRIPTION:
+# Build the wheel for the package in the current directory using PEP 517
+# backend and install it into <root>.
+#
+# This function is intended for expert use only.  It does not handle
+# wrapping executables.
+distutils_pep517_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+	[[ ${#} -eq 1 ]] || die "${FUNCNAME} takes exactly one argument: root"
+
+	if [[ ! ${DISTUTILS_USE_PEP517:-no} != no ]]; then
+		die "${FUNCNAME} is available only in PEP517 mode"
+	fi
+
+	local root=${1}
+	local -x WHEEL_BUILD_DIR=${BUILD_DIR}/wheel
+	mkdir -p "${WHEEL_BUILD_DIR}" || die
+
+	if [[ -n ${mydistutilsargs[@]} ]]; then
+		die "mydistutilsargs are banned in PEP517 mode (use DISTUTILS_ARGS)"
+	fi
+
+	local config_settings=
+	if [[ -n ${DISTUTILS_ARGS[@]} ]]; then
+		case ${DISTUTILS_USE_PEP517} in
+			setuptools)
+				config_settings=$(
+					"${EPYTHON}" - "${DISTUTILS_ARGS[@]}" <<-EOF || die
+						import json
+						import sys
+						print(json.dumps({"--global-option": sys.argv[1:]}))
+					EOF
+				)
+				;;
+			sip)
+				# NB: for practical reasons, we support only --foo=bar,
+				# not --foo bar
+				local arg
+				for arg in "${DISTUTILS_ARGS[@]}"; do
+					[[ ${arg} != -* ]] &&
+						die "Bare arguments in DISTUTILS_ARGS unsupported: ${arg}"
+				done
+
+				config_settings=$(
+					"${EPYTHON}" - "${DISTUTILS_ARGS[@]}" <<-EOF || die
+						import collections
+						import json
+						import sys
+
+						args = collections.defaultdict(list)
+						for arg in (x.split("=", 1) for x in sys.argv[1:]): \
+							args[arg[0]].extend(
+								[arg[1]] if len(arg) > 1 else [])
+
+						print(json.dumps(args))
+					EOF
+				)
+				;;
+			*)
+				die "DISTUTILS_ARGS are not supported by ${DISTUTILS_USE_PEP517}"
+				;;
+		esac
+	fi
+
+	local build_backend=$(_distutils-r1_get_backend)
+	einfo "  Building the wheel for ${PWD#${WORKDIR}/} via ${build_backend}"
+	local config_args=()
+	[[ -n ${config_settings} ]] &&
+		config_args+=( --config-json "${config_settings}" )
+	local cmd=(
+		gpep517 build-wheel
+			--backend "${build_backend}"
+			--output-fd 3
+			--wheel-dir "${WHEEL_BUILD_DIR}"
+			"${config_args[@]}"
+	)
+	printf '%s\n' "${cmd[*]}"
+	local wheel=$(
+		"${cmd[@]}" 3>&1 >&2 || die "Wheel build failed"
+	)
+	[[ -n ${wheel} ]] || die "No wheel name returned"
+
+	distutils_wheel_install "${root}" "${WHEEL_BUILD_DIR}/${wheel}"
+
+	# clean the build tree; otherwise we may end up with PyPy3
+	# extensions duplicated into CPython dists
+	if [[ ${DISTUTILS_USE_PEP517:-setuptools} == setuptools ]]; then
+		rm -rf build || die
+	fi
+}
+
+# @FUNCTION: distutils-r1_python_compile
+# @USAGE: [additional-args...]
+# @DESCRIPTION:
+# The default python_compile().
+#
+# If DISTUTILS_USE_PEP517 is set to "no", a no-op.
+#
+# If DISTUTILS_USE_PEP517 is set to any other value, builds a wheel
+# using the PEP517 backend and installs it into ${BUILD_DIR}/install.
+# May additionally call build_ext prior to that when using setuptools
+# and the eclass detects a potential benefit from parallel extension
+# builds.
+#
+# In legacy mode, runs 'esetup.py build'. Any parameters passed to this
+# function will be appended to setup.py invocation, i.e. passed
+# as options to the 'build' command.
+distutils-r1_python_compile() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	_python_check_EPYTHON
+
+	case ${DISTUTILS_USE_PEP517:-setuptools} in
+		setuptools)
+			# call setup.py build when using setuptools (either via PEP517
+			# or in legacy mode)
+
+			if [[ ${DISTUTILS_USE_PEP517} ]]; then
+				if [[ -d build ]]; then
+					eqawarn "A 'build' directory exists already.  Artifacts from this directory may"
+					eqawarn "be picked up by setuptools when building for another interpreter."
+					eqawarn "Please remove this directory prior to building."
+				fi
+			else
+				_distutils-r1_copy_egg_info
+			fi
+
+			# distutils is parallel-capable since py3.5
+			local jobs=$(makeopts_jobs "${MAKEOPTS} ${*}")
+
+			if [[ ${DISTUTILS_USE_PEP517} ]]; then
+				# issue build_ext only if it looks like we have at least
+				# two source files to build; setuptools is expensive
+				# to start and parallel builds can only benefit us if we're
+				# compiling at least two files
+				#
+				# see extension.py for list of suffixes
+				# .pyx is added for Cython
+				if [[ 1 -ne ${jobs} && 2 -eq $(
+					find '(' -name '*.c' -o -name '*.cc' -o -name '*.cpp' \
+						-o -name '*.cxx' -o -name '*.c++' -o -name '*.m' \
+						-o -name '*.mm' -o -name '*.pyx' ')' -printf '\n' |
+						head -n 2 | wc -l
+				) ]]; then
+					esetup.py build_ext -j "${jobs}" "${@}"
+				fi
+			else
+				esetup.py build -j "${jobs}" "${@}"
+			fi
+			;;
+		maturin)
+			if has_version '>=dev-util/maturin-0.13'; then
+				# auditwheel may auto-bundle libraries (bug #831171),
+				# also support cargo.eclass' IUSE=debug if available
+				local -x MATURIN_PEP517_ARGS="
+					--jobs=$(makeopts_jobs)
+					--skip-auditwheel
+					$(in_iuse debug && usex debug --profile=dev '')
+				"
+			else
+				# legacy support, can cleanup when depend on >=0.13
+				local -x MATURIN_PEP517_ARGS="
+					--skip-auditwheel
+					$(in_iuse debug && usex debug \
+						--cargo-extra-args=--profile=dev '')
+				"
+			fi
+			;;
+		no)
+			return
+			;;
+	esac
+
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		distutils_pep517_install "${BUILD_DIR}/install"
+	fi
+}
+
+# @FUNCTION: _distutils-r1_wrap_scripts
+# @USAGE: <bindir>
+# @INTERNAL
+# @DESCRIPTION:
+# Moves and wraps all installed scripts/executables as necessary.
+_distutils-r1_wrap_scripts() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	[[ ${#} -eq 1 ]] || die "usage: ${FUNCNAME} <bindir>"
+	local bindir=${1}
+
+	local scriptdir=$(python_get_scriptdir)
+	local f python_files=() non_python_files=()
+
+	if [[ -d ${D%/}${scriptdir} ]]; then
+		for f in "${D%/}${scriptdir}"/*; do
+			[[ -d ${f} ]] && die "Unexpected directory: ${f}"
+			debug-print "${FUNCNAME}: found executable at ${f#${D%/}/}"
+
+			local shebang
+			read -r shebang < "${f}"
+			if [[ ${shebang} == '#!'*${EPYTHON}* ]]; then
+				debug-print "${FUNCNAME}: matching shebang: ${shebang}"
+				python_files+=( "${f}" )
+			else
+				debug-print "${FUNCNAME}: non-matching shebang: ${shebang}"
+				non_python_files+=( "${f}" )
+			fi
+
+			mkdir -p "${D%/}${bindir}" || die
+		done
+
+		for f in "${python_files[@]}"; do
+			local basename=${f##*/}
+
+			debug-print "${FUNCNAME}: installing wrapper at ${bindir}/${basename}"
+			local dosym=dosym
+			[[ ${EAPI} == [67] ]] && dosym=dosym8
+			"${dosym}" -r /usr/lib/python-exec/python-exec2 \
+				"${bindir#${EPREFIX}}/${basename}"
+		done
+
+		for f in "${non_python_files[@]}"; do
+			local basename=${f##*/}
+
+			debug-print "${FUNCNAME}: moving ${f#${D%/}/} to ${bindir}/${basename}"
+			mv "${f}" "${D%/}${bindir}/${basename}" || die
+		done
+	fi
+}
+
+# @FUNCTION: distutils-r1_python_test
+# @USAGE: [additional-args...]
+# @DESCRIPTION:
+# The python_test() implementation used by distutils_enable_tests.
+# Runs tests using the specified test runner, possibly installing them
+# first.
+#
+# This function is used only if distutils_enable_tests is called.
+distutils-r1_python_test() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	if [[ -z ${_DISTUTILS_TEST_RUNNER} ]]; then
+		die "${FUNCNAME} can be only used after calling distutils_enable_tests"
+	fi
+
+	_python_check_EPYTHON
+
+	if [[ ${_DISTUTILS_TEST_INSTALL} ]]; then
+		distutils_install_for_testing
+	fi
+
+	case ${_DISTUTILS_TEST_RUNNER} in
+		nose)
+			"${EPYTHON}" -m nose -v "${@}"
+			;;
+		pytest)
+			epytest
+			;;
+		setup.py)
+			nonfatal esetup.py test --verbose
+			;;
+		unittest)
+			eunittest
+			;;
+		*)
+			die "Mis-synced test runner between ${FUNCNAME} and distutils_enable_testing"
+			;;
+	esac
+
+	if [[ ${?} -ne 0 ]]; then
+		die "Tests failed with ${EPYTHON}"
+	fi
+}
+
+# @FUNCTION: distutils-r1_python_install
+# @USAGE: [additional-args...]
+# @DESCRIPTION:
+# The default python_install().
+#
+# In PEP517 mode, merges the files from ${BUILD_DIR}/install
+# (if present) to the image directory.
+#
+# In the legacy mode, calls `esetup.py install` to install the package.
+# Any parameters passed to this function will be appended
+# to the setup.py invocation (i.e. as options to the 'install' command).
+distutils-r1_python_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	_python_check_EPYTHON
+
+	local scriptdir=${EPREFIX}/usr/bin
+	local merge_root=
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		local root=${BUILD_DIR}/install
+		local reg_scriptdir=${root}/${scriptdir}
+		local wrapped_scriptdir=${root}$(python_get_scriptdir)
+
+		# we are assuming that _distutils-r1_post_python_compile
+		# has been called and ${root} has not been altered since
+		# let's explicitly verify these assumptions
+
+		# remove files that we've created explicitly
+		rm "${reg_scriptdir}"/{"${EPYTHON}",python3,python,pyvenv.cfg} || die
+
+		# Automagically do the QA check to avoid issues when bootstrapping
+		# prefix.
+		if type diff &>/dev/null ; then
+			# verify that scriptdir & wrapped_scriptdir both contain
+			# the same files
+			(
+				cd "${reg_scriptdir}" && find . -mindepth 1
+			) | sort > "${T}"/.distutils-files-bin
+			assert "listing ${reg_scriptdir} failed"
+			(
+				if [[ -d ${wrapped_scriptdir} ]]; then
+					cd "${wrapped_scriptdir}" && find . -mindepth 1
+				fi
+			) | sort > "${T}"/.distutils-files-wrapped
+			assert "listing ${wrapped_scriptdir} failed"
+			if ! diff -U 0 "${T}"/.distutils-files-{bin,wrapped}; then
+				die "File lists for ${reg_scriptdir} and ${wrapped_scriptdir} differ (see diff above)"
+			fi
+		fi
+
+		# remove the altered bindir, executables from the package
+		# are already in scriptdir
+		rm -r "${reg_scriptdir}" || die
+		if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
+			if [[ -d ${wrapped_scriptdir} ]]; then
+				mv "${wrapped_scriptdir}" "${reg_scriptdir}" || die
+			fi
+		fi
+		# prune empty directories to see if ${root} contains anything
+		# to merge
+		find "${BUILD_DIR}"/install -type d -empty -delete || die
+		[[ -d ${BUILD_DIR}/install ]] && merge_root=1
+	else
+		local root=${D%/}/_${EPYTHON}
+		[[ ${DISTUTILS_SINGLE_IMPL} ]] && root=${D%/}
+
+		# inline DISTUTILS_ARGS logic from esetup.py in order to make
+		# argv overwriting easier
+		local args=(
+			"${DISTUTILS_ARGS[@]}"
+			"${mydistutilsargs[@]}"
+			install --skip-build --root="${root}" "${args[@]}"
+			"${@}"
+		)
+		local DISTUTILS_ARGS=()
+		local mydistutilsargs=()
+
+		# enable compilation for the install phase.
+		local -x PYTHONDONTWRITEBYTECODE=
+
+		# python likes to compile any module it sees, which triggers sandbox
+		# failures if some packages haven't compiled their modules yet.
+		addpredict "${EPREFIX}/usr/lib/${EPYTHON}"
+		addpredict "${EPREFIX}/usr/lib/pypy3.9"
+		addpredict "${EPREFIX}/usr/local" # bug 498232
+
+		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+			merge_root=1
+
+			# user may override --install-scripts
+			# note: this is poor but distutils argv parsing is dumb
+
+			# rewrite all the arguments
+			set -- "${args[@]}"
+			args=()
+			while [[ ${@} ]]; do
+				local a=${1}
+				shift
+
+				case ${a} in
+					--install-scripts=*)
+						scriptdir=${a#--install-scripts=}
+						;;
+					--install-scripts)
+						scriptdir=${1}
+						shift
+						;;
+					*)
+						args+=( "${a}" )
+						;;
+				esac
+			done
+		fi
+
+		esetup.py "${args[@]}"
+	fi
+
+	if [[ ${merge_root} ]]; then
+		multibuild_merge_root "${root}" "${D%/}"
+	fi
+	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+		_distutils-r1_wrap_scripts "${scriptdir}"
+	fi
+}
+
+# @FUNCTION: distutils-r1_python_install_all
+# @DESCRIPTION:
+# The default python_install_all(). It installs the documentation.
+distutils-r1_python_install_all() {
+	debug-print-function ${FUNCNAME} "${@}"
+	_distutils-r1_check_all_phase_mismatch
+
+	einstalldocs
+}
+
+# @FUNCTION: distutils-r1_run_phase
+# @USAGE: [<argv>...]
+# @INTERNAL
+# @DESCRIPTION:
+# Run the given command.
+#
+# If out-of-source builds are used, the phase function is run in source
+# directory, with BUILD_DIR pointing at the build directory
+# and PYTHONPATH having an entry for the module build directory.
+#
+# If in-source builds are used, the command is executed in the directory
+# holding the per-implementation copy of sources. BUILD_DIR points
+# to the 'build' subdirectory.
+distutils-r1_run_phase() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	if [[ ${DISTUTILS_IN_SOURCE_BUILD} ]]; then
+		[[ ${DISTUTILS_USE_PEP517} ]] &&
+			die "DISTUTILS_IN_SOURCE_BUILD is not supported in PEP517 mode"
+		# only force BUILD_DIR if implementation is explicitly enabled
+		# for building; any-r1 API may select one that is not
+		# https://bugs.gentoo.org/701506
+		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]] &&
+				has "${EPYTHON/./_}" ${PYTHON_TARGETS}; then
+			cd "${BUILD_DIR}" || die
+		fi
+		local BUILD_DIR=${BUILD_DIR}/build
+	fi
+
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		local -x PATH=${BUILD_DIR}/install${EPREFIX}/usr/bin:${PATH}
+	else
+		local -x PYTHONPATH="${BUILD_DIR}/lib:${PYTHONPATH}"
+
+		# make PATH local for distutils_install_for_testing calls
+		# it makes little sense to let user modify PATH in per-impl phases
+		# and _all() already localizes it
+		local -x PATH=${PATH}
+
+		# Undo the default switch in setuptools-60+ for the time being,
+		# to avoid replacing .egg-info file with directory in-place.
+		local -x SETUPTOOLS_USE_DISTUTILS="${SETUPTOOLS_USE_DISTUTILS:-stdlib}"
+
+		# Bug 559644
+		# using PYTHONPATH when the ${BUILD_DIR}/lib is not created yet might lead to
+		# problems in setup.py scripts that try to import modules/packages from that path
+		# during the build process (Python at startup evaluates PYTHONPATH, if the dir is
+		# not valid then associates a NullImporter object to ${BUILD_DIR}/lib storing it
+		# in the sys.path_importer_cache)
+		mkdir -p "${BUILD_DIR}/lib" || die
+	fi
+
+	# Set up build environment, bug #513664.
+	local -x AR=${AR} CC=${CC} CPP=${CPP} CXX=${CXX}
+	tc-export AR CC CPP CXX
+
+	# How to build Python modules in different worlds...
+	local ldopts
+	case "${CHOST}" in
+		# provided by haubi, 2014-07-08
+		*-aix*) ldopts='-shared -Wl,-berok';; # good enough
+		# provided by grobian, 2014-06-22, bug #513664 c7
+		*-darwin*) ldopts='-bundle -undefined dynamic_lookup';;
+		*) ldopts='-shared';;
+	esac
+
+	local -x LDSHARED="${CC} ${ldopts}" LDCXXSHARED="${CXX} ${ldopts}"
+	local _DISTUTILS_POST_PHASE_RM=()
+
+	"${@}"
+	local ret=${?}
+
+	if [[ -n ${_DISTUTILS_POST_PHASE_RM} ]]; then
+		rm "${_DISTUTILS_POST_PHASE_RM[@]}" || die
+	fi
+
+	cd "${_DISTUTILS_INITIAL_CWD}" || die
+	if [[ ! ${_DISTUTILS_IN_COMMON_IMPL} ]] &&
+		declare -f "_distutils-r1_post_python_${EBUILD_PHASE}" >/dev/null
+	then
+		"_distutils-r1_post_python_${EBUILD_PHASE}"
+	fi
+	return "${ret}"
+}
+
+# @FUNCTION: _distutils-r1_run_common_phase
+# @USAGE: [<argv>...]
+# @INTERNAL
+# @DESCRIPTION:
+# Run the given command, restoring the state for a most preferred Python
+# implementation matching DISTUTILS_ALL_SUBPHASE_IMPLS.
+#
+# If in-source build is used, the command will be run in the copy
+# of sources made for the selected Python interpreter.
+_distutils-r1_run_common_phase() {
+	local DISTUTILS_ORIG_BUILD_DIR=${BUILD_DIR}
+	local _DISTUTILS_IN_COMMON_IMPL=1
+
+	if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
+		# reuse the dedicated code branch
+		_distutils-r1_run_foreach_impl "${@}"
+	else
+		local -x EPYTHON PYTHON
+		local -x PATH=${PATH} PKG_CONFIG_PATH=${PKG_CONFIG_PATH}
+		python_setup "${DISTUTILS_ALL_SUBPHASE_IMPLS[@]}"
+
+		local MULTIBUILD_VARIANTS=( "${EPYTHON/./_}" )
+		# store for restoring after distutils-r1_run_phase.
+		local _DISTUTILS_INITIAL_CWD=${PWD}
+		multibuild_foreach_variant \
+			distutils-r1_run_phase "${@}"
+	fi
+}
+
+# @FUNCTION: _distutils-r1_run_foreach_impl
+# @INTERNAL
+# @DESCRIPTION:
+# Run the given phase for each implementation if multiple implementations
+# are enabled, once otherwise.
+_distutils-r1_run_foreach_impl() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	# store for restoring after distutils-r1_run_phase.
+	local _DISTUTILS_INITIAL_CWD=${PWD}
+	set -- distutils-r1_run_phase "${@}"
+
+	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
+		local _DISTUTILS_CALLING_FOREACH_IMPL=1
+		python_foreach_impl "${@}"
+	else
+		if [[ ! ${EPYTHON} ]]; then
+			die "EPYTHON unset, python-single-r1_pkg_setup not called?!"
+		fi
+		local BUILD_DIR=${BUILD_DIR:-${S}}
+		BUILD_DIR=${BUILD_DIR%%/}_${EPYTHON}
+
+		"${@}"
+	fi
+}
+
+distutils-r1_src_prepare() {
+	debug-print-function ${FUNCNAME} "${@}"
+	local ret=0
+	local _DISTUTILS_DEFAULT_CALLED
+
+	# common preparations
+	if declare -f python_prepare_all >/dev/null; then
+		python_prepare_all || ret=${?}
+	else
+		distutils-r1_python_prepare_all || ret=${?}
+	fi
+
+	if [[ ! ${_DISTUTILS_DEFAULT_CALLED} ]]; then
+		die "QA: python_prepare_all() didn't call distutils-r1_python_prepare_all"
+	fi
+
+	if declare -f python_prepare >/dev/null; then
+		_distutils-r1_run_foreach_impl python_prepare || ret=${?}
+	fi
+
+	return ${ret}
+}
+
+distutils-r1_src_configure() {
+	debug-print-function ${FUNCNAME} "${@}"
+	local ret=0
+
+	if declare -f python_configure >/dev/null; then
+		_distutils-r1_run_foreach_impl python_configure || ret=${?}
+	fi
+
+	if declare -f python_configure_all >/dev/null; then
+		_distutils-r1_run_common_phase python_configure_all || ret=${?}
+	fi
+
+	return ${ret}
+}
+
+# @FUNCTION: _distutils-r1_post_python_compile
+# @INTERNAL
+# @DESCRIPTION:
+# Post-phase function called after python_compile.  In PEP517 mode,
+# it adjusts the install tree for venv-style usage.
+_distutils-r1_post_python_compile() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local root=${BUILD_DIR}/install
+	if [[ ${DISTUTILS_USE_PEP517} && -d ${root} ]]; then
+		# copy executables to python-exec directory
+		# we do it early so that we can alter bindir recklessly
+		local bindir=${root}${EPREFIX}/usr/bin
+		local rscriptdir=${root}$(python_get_scriptdir)
+		[[ -d ${rscriptdir} ]] &&
+			die "${rscriptdir} should not exist!"
+		if [[ -d ${bindir} ]]; then
+			mkdir -p "${rscriptdir}" || die
+			cp -a --reflink=auto "${bindir}"/. "${rscriptdir}"/ || die
+		fi
+
+		# enable venv magic inside the install tree
+		mkdir -p "${bindir}" || die
+		ln -s "${PYTHON}" "${bindir}/${EPYTHON}" || die
+		ln -s "${EPYTHON}" "${bindir}/python3" || die
+		ln -s "${EPYTHON}" "${bindir}/python" || die
+		cat > "${bindir}"/pyvenv.cfg <<-EOF || die
+			include-system-site-packages = true
+		EOF
+
+		# we need to change shebangs to point to the venv-python
+		find "${bindir}" -type f -exec sed -i \
+			-e "1s@^#!\(${EPREFIX}/usr/bin/\(python\|pypy\)\)@#!${root}\1@" \
+			{} + || die
+	fi
+}
+
+distutils-r1_src_compile() {
+	debug-print-function ${FUNCNAME} "${@}"
+	local ret=0
+
+	if declare -f python_compile >/dev/null; then
+		_distutils-r1_run_foreach_impl python_compile || ret=${?}
+	else
+		_distutils-r1_run_foreach_impl distutils-r1_python_compile || ret=${?}
+	fi
+
+	if declare -f python_compile_all >/dev/null; then
+		_distutils-r1_run_common_phase python_compile_all || ret=${?}
+	fi
+
+	return ${ret}
+}
+
+# @FUNCTION: _distutils-r1_clean_egg_info
+# @INTERNAL
+# @DESCRIPTION:
+# Clean up potential stray egg-info files left by setuptools test phase.
+# Those files ended up being unversioned, and caused issues:
+# https://bugs.gentoo.org/534058
+_distutils-r1_clean_egg_info() {
+	if [[ ${DISTUTILS_USE_PEP517} ]]; then
+		die "${FUNCNAME} is not implemented in PEP517 mode"
+	fi
+
+	rm -rf "${BUILD_DIR}"/lib/*.egg-info || die
+}
+
+# @FUNCTION: _distutils-r1_post_python_test
+# @INTERNAL
+# @DESCRIPTION:
+# Post-phase function called after python_test.
+_distutils-r1_post_python_test() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	if [[ ! ${DISTUTILS_USE_PEP517} ]]; then
+		_distutils-r1_clean_egg_info
+	fi
+}
+
+distutils-r1_src_test() {
+	debug-print-function ${FUNCNAME} "${@}"
+	local ret=0
+
+	if declare -f python_test >/dev/null; then
+		_distutils-r1_run_foreach_impl python_test || ret=${?}
+	fi
+
+	if declare -f python_test_all >/dev/null; then
+		_distutils-r1_run_common_phase python_test_all || ret=${?}
+	fi
+
+	return ${ret}
+}
+
+# @FUNCTION: _distutils-r1_post_python_install
+# @INTERNAL
+# @DESCRIPTION:
+# Post-phase function called after python_install.  Performs QA checks.
+# In PEP517 mode, additionally optimizes installed Python modules.
+_distutils-r1_post_python_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local sitedir=${D%/}$(python_get_sitedir)
+	if [[ -d ${sitedir} ]]; then
+		local forbidden_package_names=(
+			examples test tests
+			.pytest_cache .hypothesis _trial_temp
+		)
+		local p
+		for p in "${forbidden_package_names[@]}"; do
+			if [[ -d ${sitedir}/${p} ]]; then
+				die "Package installs '${p}' package which is forbidden and likely a bug in the build system."
+			fi
+		done
+
+		if [[ ${DISTUTILS_USE_PEP517} ]]; then
+			if ! has_version -b ">=dev-python/gpep517-9"
+			then
+				# TODO: remove when we dep on >=9
+				# we need to recompile everything here in order to embed
+				# the correct paths
+				python_optimize "${sitedir}"
+			fi
+		fi
+	fi
+}
+
+# @FUNCTION: _distutils-r1_check_namespace_pth
+# @INTERNAL
+# @DESCRIPTION:
+# Check if any *-nspkg.pth files were installed (by setuptools)
+# and warn about the policy non-conformance if they were.
+_distutils-r1_check_namespace_pth() {
+	local f pth=()
+
+	while IFS= read -r -d '' f; do
+		pth+=( "${f}" )
+	done < <(find "${ED%/}" -name '*-nspkg.pth' -print0)
+
+	if [[ ${pth[@]} ]]; then
+		ewarn "The following *-nspkg.pth files were found installed:"
+		ewarn
+		for f in "${pth[@]}"; do
+			ewarn "  ${f#${ED%/}}"
+		done
+		ewarn
+		ewarn "The presence of those files may break namespaces in Python 3.5+. Please"
+		ewarn "read our documentation on reliable handling of namespaces and update"
+		ewarn "the ebuild accordingly:"
+		ewarn
+		ewarn "  https://projects.gentoo.org/python/guide/concept.html#namespace-packages"
+
+		if ! has "${EAPI}" 6 7 8; then
+			die "*-nspkg.pth files are banned in EAPI ${EAPI}"
+		fi
+	fi
+}
+
+distutils-r1_src_install() {
+	debug-print-function ${FUNCNAME} "${@}"
+	local ret=0
+
+	if declare -f python_install >/dev/null; then
+		_distutils-r1_run_foreach_impl python_install || ret=${?}
+	else
+		_distutils-r1_run_foreach_impl distutils-r1_python_install || ret=${?}
+	fi
+
+	if declare -f python_install_all >/dev/null; then
+		_distutils-r1_run_common_phase python_install_all || ret=${?}
+	else
+		_distutils-r1_run_common_phase distutils-r1_python_install_all || ret=${?}
+	fi
+
+	_distutils-r1_check_namespace_pth
+
+	return ${ret}
+}
+
+_DISTUTILS_R1=1
+fi