python3: Port changes from python-package.mk to python3-package.mk

- Add configure arguments for distutils path detection
- Add '_python_*' env vars to host python

Signed-off-by: Florian Fieber <florian@florianfieber.de>

lang/python3/files/python3-package.mk

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2007-2014 OpenWrt.org
+# Copyright (C) 2007-2015 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -28,11 +28,21 @@ define HostPython3
 	(	export PYTHONPATH="$(PYTHON3PATH)"; \
 		export PYTHONOPTIMIZE=""; \
 		export PYTHONDONTWRITEBYTECODE=1; \
+		export _python_sysroot="$(STAGING_DIR)"; \
+		export _python_prefix="/usr"; \
+		export _python_exec_prefix="/usr"; \
 		$(1) \
 		$(HOST_PYTHON3_BIN) $(2); \
 	)
 endef
 
+# These configure args are needed in detection of path to Python header files
+# using autotools.
+CONFIGURE_ARGS += \
+	_python_sysroot="$(STAGING_DIR)" \
+	_python_prefix="/usr" \
+	_python_exec_prefix="/usr"
+
 PKG_USE_MIPS16:=0
 # This is required in addition to PKG_USE_MIPS16:=0 because otherwise MIPS16
 # flags are inherited from the Python base package (via sysconfig module)