openWRT Makefile for python backports-abc - openwrt

Question

I'm attempting to build the backports-abc python module in to my OpenWRT build, and need a bit of help on the build/extraction process.
My issue seems to be that the downloaded backports-abc tar file extracts the content to backports_abc-0.5 due to the underlying tar file structure, but the build process is looking for the setup.py etc under backports-abc-0.5 (see below). I can manually copy the files over and rebuild, and that works fine, but that's not ideal. Also, though it builds OK, when I load the image to the device, the backports module is missing.
/home/ubuntu/build2/openwrt/staging_dir/host/bin/python2: can't open file './setup.py': [Errno 2] No such file or directory
Makefile:59: recipe for target '/home/ubuntu/build2/openwrt/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/backports-abc-0.5//.built' failed
make[3]: *** [/home/ubuntu/build2/openwrt/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/backports-abc-0.5//.built] Error 2
make[3]: Leaving directory '/home/ubuntu/build2/openwrt/feeds/linkit/python-backports-abc
'
The openWRT documentation around Makefiles is a bit vague, and so is my understanding of the process.
How do I get the tar file extracted to the right folder, or where in the Makefile process should I just copy the files to a correct folder?
Here's my Makefile.
include $(TOPDIR)/rules.mk
PKG_NAME:=backports_abc
PKG_VERSION:=0.5
PKG_RELEASE:=1
PKG_SOURCE:=backports_abc-0.5.tar.gz
PKG_SOURCE_URL:=https://pypi.python.org/packages/68/3c/1317a9113c377d1e33711ca8de1e80afbaf4a3c950dd0edfaf61f9bfe6d8/
PKG_MD5SUM:=7d1936ec183a3586290adf60f6f96764
PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)/
#PKG_BUILD_DEPENDS:=python-setuptools
include $(INCLUDE_DIR)/package.mk
$(call include_mk, python-package.mk)
define Package/backports_abc
SECTION:=lang-python
CATEGORY:=Languages
SUBMENU:=Python
TITLE:=backports_abc
URL:=https://pypi.python.org/pypi/backports_abc/0.5
DEPENDS:=+python
endef
define Package/backports_abc/description
A backport of recent additions to the 'collections.abc' module.
endef
define Build/Compile
$(call Build/Compile/PyMod,., \
install --prefix="/usr" --root="$(PKG_INSTALL_DIR)" \
)
endef
define Build/InstallDev
$(INSTALL_DIR) $(STAGING_DIR)$(PYTHON_PKG_DIR)
$(CP) \
$(PKG_INSTALL_DIR)$(PYTHON_PKG_DIR)/* \
$(STAGING_DIR)$(PYTHON_PKG_DIR)/
[ ! -e $(PKG_INSTALL_DIR)/usr/include ] || $(CP) \
$(PKG_INSTALL_DIR)/usr/include/* \
$(STAGING_DIR)/usr/include/
endef
define Package/backportsabc/install
$(INSTALL_DIR) $(1)$(PYTHON_PKG_DIR)/
$(CP) \
$(PKG_INSTALL_DIR)$(PYTHON_PKG_DIR)/* \
$(1)$(PYTHON_PKG_DIR)/
endef
$(eval $(call BuildPackage,backports_abc))

Answer 1

Copy your Makefile somewhere in packages directory, and to overcome the issue remove PKG_BUILD_DIR variable from your Makefile.

Answer 2

I resolved this by fixing up some underscores and hyphens... ie: backports_abc and backports-abc
Basically..
This... PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)/
meant that it was looking for the files based on the PKG_NAME variable.
include $(TOPDIR)/rules.mk
PKG_NAME:=backports_abc
PKG_VERSION:=0.5
PKG_RELEASE:=1
PKG_SOURCE:=backports_abc-0.5.tar.gz
PKG_SOURCE_URL:=https://pypi.python.org/packages/68/3c/1317a9113c377d1e33711ca8de1e80afbaf4a3c950dd0edfaf61f9bfe6d8/
PKG_MD5SUM:=7d1936ec183a3586290adf60f6f96764
PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(PKG_VERSION)/
#PKG_BUILD_DEPENDS:=python-setuptools
include $(INCLUDE_DIR)/package.mk
$(call include_mk, python-package.mk)
define Package/backports-abc
SECTION:=lang-python
CATEGORY:=Languages
SUBMENU:=Python
TITLE:=backports-abc
URL:=https://pypi.python.org/pypi/backports_abc/0.5
DEPENDS:=+python
endef
define Package/backports-abc/description
A backport of recent additions to the 'collections.abc' module.
endef
define Build/Compile
$(call Build/Compile/PyMod,., \
install --prefix="/usr" --root="$(PKG_INSTALL_DIR)" \
)
endef
define Build/InstallDev
$(INSTALL_DIR) $(STAGING_DIR)$(PYTHON_PKG_DIR)
$(CP) \
$(PKG_INSTALL_DIR)$(PYTHON_PKG_DIR)/* \
$(STAGING_DIR)$(PYTHON_PKG_DIR)/
[ ! -e $(PKG_INSTALL_DIR)/usr/include ] || $(CP) \
$(PKG_INSTALL_DIR)/usr/include/* \
$(STAGING_DIR)/usr/include/
endef
define Package/backports-abc/install
$(INSTALL_DIR) $(1)$(PYTHON_PKG_DIR)/
$(CP) \
$(PKG_INSTALL_DIR)$(PYTHON_PKG_DIR)/* \
$(1)$(PYTHON_PKG_DIR)/
endef
$(eval $(call BuildPackage,backports-abc))