diff --git a/eclass/python-utils-r1.eclass b/eclass/python-utils-r1.eclass
index 3482919cd9..ec1a3d2006 100644
--- a/eclass/python-utils-r1.eclass
+++ b/eclass/python-utils-r1.eclass
@@ -340,6 +340,17 @@ _python_export() {
 				fi
 				debug-print "${FUNCNAME}: PYTHON = ${PYTHON}"
 				;;
+			PYTHON_STDLIB)
+				[[ -n ${PYTHON} ]] || die "PYTHON needs to be set for ${var} to be exported, or requested before it"
+				PYTHON_STDLIB=$(
+					"${PYTHON}" - "${EPREFIX}/usr" <<-EOF || die
+						import sys, sysconfig
+						print(sysconfig.get_path("stdlib", vars={"installed_base": sys.argv[1]}))
+					EOF
+				)
+				export PYTHON_STDLIB
+				debug-print "${FUNCNAME}: PYTHON_STDLIB = ${PYTHON_STDLIB}"
+				;;
 			PYTHON_SITEDIR)
 				[[ -n ${PYTHON} ]] || die "PYTHON needs to be set for ${var} to be exported, or requested before it"
 				PYTHON_SITEDIR=$(
@@ -482,6 +493,18 @@ _python_export() {
 	done
 }
 
+# @FUNCTION: python_get_stdlib
+# @USAGE: [<impl>]
+# @DESCRIPTION:
+# Obtain and print the 'stdlib' path for the given implementation. If no
+# implementation is provided, ${EPYTHON} will be used.
+python_get_stdlib() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	_python_export "${@}" PYTHON_STDLIB
+	echo "${PYTHON_STDLIB}"
+}
+
 # @FUNCTION: python_get_sitedir
 # @USAGE: [<impl>]
 # @DESCRIPTION:
@@ -1337,6 +1360,15 @@ _python_check_occluded_packages() {
 # Specifies the number of jobs for parallel (pytest-xdist) test runs.
 # When unset, defaults to -j from MAKEOPTS, or the current nproc.
 
+# @ECLASS_VARIABLE: EPYTEST_FLAGS
+# @USER_VARIABLE
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# Additional flags to pass to pytest.  This is intended to be set
+# in the environment when debugging packages (options such as -x or -s
+# are useful here), rather than globally.  It must not be set
+# in ebuilds.
+
 # @FUNCTION: epytest
 # @USAGE: [<args>...]
 # @DESCRIPTION:
@@ -1448,10 +1480,10 @@ epytest() {
 	for x in "${EPYTEST_IGNORE[@]}"; do
 		args+=( --ignore "${x}" )
 	done
-	set -- "${EPYTHON}" -m pytest "${args[@]}" "${@}"
+	set -- "${EPYTHON}" -m pytest "${args[@]}" "${@}" ${EPYTEST_FLAGS}
 
 	echo "${@}" >&2
-	"${@}" || die -n "pytest failed with ${EPYTHON}"
+	"${@}"
 	local ret=${?}
 
 	# remove common temporary directories left over by pytest plugins
@@ -1462,6 +1494,7 @@ epytest() {
 		find "${BUILD_DIR}" -name '*-pytest-*.pyc' -delete || die
 	fi
 
+	[[ ${ret} -ne 0 ]] && die -n "pytest failed with ${EPYTHON}"
 	return ${ret}
 }
 
@@ -1550,4 +1583,38 @@ python_has_version() {
 	return 0
 }
 
+# @FUNCTION: _python_sanity_checks
+# @INTERNAL
+# @DESCRIPTION:
+# Perform additional environment sanity checks.
+_python_sanity_checks() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	[[ ${_PYTHON_SANITY_CHECKED} ]] && return
+
+	if [[ -v PYTHONPATH ]]; then
+		local x paths=()
+		mapfile -d ':' -t paths <<<${PYTHONPATH}
+
+		for x in "${paths[@]}"; do
+			if [[ ${x} != /* ]]; then
+				eerror "Relative path found in PYTHONPATH:"
+				eerror
+				eerror "  PYTHONPATH=${PYTHONPATH@Q}"
+				eerror
+				eerror "This is guaranteed to cause random breakage.  Please make sure that"
+				eerror "your PYTHONPATH contains absolute paths only (and only if necessary)."
+				eerror "Note that empty values (including ':' at either end and an empty"
+				eerror "PYTHONPATH) count as the current directory.  If no PYTHONPATH"
+				eerror "is intended, it needs to be unset instead."
+				die "Relative paths in PYTHONPATH are forbidden: ${x@Q}"
+			fi
+		done
+
+		elog "PYTHONPATH=${PYTHONPATH@Q}"
+	fi
+
+	_PYTHON_SANITY_CHECKED=1
+}
+
 fi