python,python3: Add PYTHON_PKG_SETUP_DIR

This adds a variable (PYTHON_PKG_SETUP_DIR / PYTHON3_PKG_SETUP_DIR) that
allows a Python package Makefile to control the directory where setup.py
is called (as part of PyBuild/Compile/Default /
Py3Build/Compile/Default).

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python/python-package.mk

@@ -114,6 +114,7 @@ define Build/Compile/PyMod
 		$(3))
 endef
 
+PYTHON_PKG_SETUP_DIR ?=
 PYTHON_PKG_SETUP_ARGS:=--single-version-externally-managed
 PYTHON_PKG_SETUP_VARS:=
 
@@ -121,7 +122,8 @@ define PyBuild/Compile/Default
 	$(foreach pkg,$(HOST_PYTHON_PACKAGE_BUILD_DEPENDS),
 		$(call host_python_pip_install_host,$(pkg))
 	)
-	$(call Build/Compile/PyMod,, \
+	$(call Build/Compile/PyMod, \
+		$(PYTHON_PKG_SETUP_DIR), \
 		install --prefix="/usr" --root="$(PKG_INSTALL_DIR)" \
 		$(PYTHON_PKG_SETUP_ARGS), \
 		$(PYTHON_PKG_SETUP_VARS) \

lang/python/python3-package.mk

@@ -113,6 +113,7 @@ define Build/Compile/Py3Mod
 		$(3))
 endef
 
+PYTHON3_PKG_SETUP_DIR ?=
 PYTHON3_PKG_SETUP_ARGS:=--single-version-externally-managed
 PYTHON3_PKG_SETUP_VARS:=
 
@@ -120,7 +121,8 @@ define Py3Build/Compile/Default
 	$(foreach pkg,$(HOST_PYTHON3_PACKAGE_BUILD_DEPENDS),
 		$(call host_python3_pip_install_host,$(pkg))
 	)
-	$(call Build/Compile/Py3Mod,, \
+	$(call Build/Compile/Py3Mod, \
+		$(PYTHON3_PKG_SETUP_DIR), \
 		install --prefix="/usr" --root="$(PKG_INSTALL_DIR)" \
 		$(PYTHON3_PKG_SETUP_ARGS), \
 		$(PYTHON3_PKG_SETUP_VARS) \