From 6ef46bb9194b5d3f5fc17471d8869bcae729d215 Mon Sep 17 00:00:00 2001
From: Jeffery To <jeffery.to@gmail.com>
Date: Thu, 2 Mar 2023 23:35:00 +0800
Subject: [PATCH] python: Unset Python environment variables

This will prevent the user's environment variables from affecting host
Python, removing the need to manually override these variables.

It is also not necessary to set PYTHONPATH (when not working on target
Python packages) because the given directories are already included in
Python's search path by default.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>
---
 lang/python/python3-host.mk    | 50 +++++++++++++++++++++++++++++++---
 lang/python/python3-package.mk |  1 -
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/lang/python/python3-host.mk b/lang/python/python3-host.mk
index 8a05c332cf..fdf6658fd8 100644
--- a/lang/python/python3-host.mk
+++ b/lang/python/python3-host.mk
@@ -12,6 +12,51 @@
 python3_mk_path:=$(dir $(lastword $(MAKEFILE_LIST)))
 include $(python3_mk_path)python3-version.mk
 
+# Unset environment variables
+
+# https://docs.python.org/3/using/cmdline.html#environment-variables
+unexport \
+	PYTHONHOME \
+	PYTHONPATH \
+	PYTHONSAFEPATH \
+	PYTHONPLATLIBDIR \
+	PYTHONSTARTUP \
+	PYTHONOPTIMIZE \
+	PYTHONBREAKPOINT \
+	PYTHONDEBUG \
+	PYTHONINSPECT \
+	PYTHONUNBUFFERED \
+	PYTHONVERBOSE \
+	PYTHONCASEOK \
+	PYTHONDONTWRITEBYTECODE \
+	PYTHONPYCACHEPREFIX \
+	PYTHONHASHSEED \
+	PYTHONINTMAXSTRDIGITS \
+	PYTHONIOENCODING \
+	PYTHONNOUSERSITE \
+	PYTHONUSERBASE \
+	PYTHONEXECUTABLE \
+	PYTHONWARNINGS \
+	PYTHONFAULTHANDLER \
+	PYTHONTRACEMALLOC \
+	PYTHONPROFILEIMPORTTIME \
+	PYTHONASYNCIODEBUG \
+	PYTHONMALLOC \
+	PYTHONMALLOCSTATS \
+	PYTHONLEGACYWINDOWSFSENCODING \
+	PYTHONLEGACYWINDOWSSTDIO \
+	PYTHONCOERCECLOCALE \
+	PYTHONDEVMODE \
+	PYTHONUTF8 \
+	PYTHONWARNDEFAULTENCODING \
+	PYTHONNODEBUGRANGES
+
+# https://docs.python.org/3/using/cmdline.html#debug-mode-variables
+unexport \
+	PYTHONTHREADDEBUG \
+	PYTHONDUMPREFS \
+	PYTHONDUMPREFSFILE
+
 HOST_PYTHON3_DIR:=$(STAGING_DIR_HOSTPKG)
 HOST_PYTHON3_INC_DIR:=$(HOST_PYTHON3_DIR)/include/python$(PYTHON3_VERSION)
 HOST_PYTHON3_LIB_DIR:=$(HOST_PYTHON3_DIR)/lib/python$(PYTHON3_VERSION)
@@ -31,10 +76,7 @@ HOST_PYTHON3_VARS = \
 	LDSHARED="$(HOSTCC) -shared" \
 	CFLAGS="$(HOST_CFLAGS)" \
 	CPPFLAGS="$(HOST_CPPFLAGS) -I$(HOST_PYTHON3_INC_DIR)" \
-	LDFLAGS="$(HOST_LDFLAGS) -lpython$(PYTHON3_VERSION) -Wl$(comma)-rpath$(comma)$(STAGING_DIR_HOSTPKG)/lib" \
-	PYTHONPATH="$(HOST_PYTHON3PATH)" \
-	PYTHONDONTWRITEBYTECODE=0 \
-	PYTHONOPTIMIZE=""
+	LDFLAGS="$(HOST_LDFLAGS) -lpython$(PYTHON3_VERSION) -Wl$(comma)-rpath$(comma)$(STAGING_DIR_HOSTPKG)/lib"
 
 # $(1) => directory of python script
 # $(2) => python script and its arguments
diff --git a/lang/python/python3-package.mk b/lang/python/python3-package.mk
index a24892ac57..8477d8c75d 100644
--- a/lang/python/python3-package.mk
+++ b/lang/python/python3-package.mk
@@ -42,7 +42,6 @@ PYTHON3_VARS = \
 	__PYVENV_LAUNCHER__="/usr/bin/$(PYTHON3)" \
 	PYTHONPATH="$(PYTHON3PATH)" \
 	PYTHONDONTWRITEBYTECODE=1 \
-	PYTHONOPTIMIZE="" \
 	_python_sysroot="$(STAGING_DIR)" \
 	_python_prefix="/usr" \
 	_python_exec_prefix="/usr"