node-cylon: fix issues with node 8.11.3

Get node version from node executable instead of keeping it hardcoded to
the Makefile.

Current version of npm install installs a link to the build directory.
The workaround is to use npm pack to make a tarball and install from
that.
npm also adds useless metadata to package.json exposing
PKG_BUILD_DIR, so it needs to be stripped.

Signed-off-by: Eneas U de Queiroz <cote2004-github@yahoo.com>

lang/node-cylon/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 PKG_NPM_NAME:=cylon
 PKG_NAME:=node-$(PKG_NPM_NAME)
 PKG_VERSION:=0.24.0
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/hybridgroup/cylon-firmata.git
@@ -20,7 +20,7 @@ PKG_SOURCE:=$(PKG_NAME)-$(PKG_SOURCE_VERSION).tar.gz
 PKG_MIRROR_HASH:=dceb75539d32f402db0a5f68f2c7e2b52e5547a5ac2dec875d34fd3cc95cce00
 
 PKG_BUILD_DEPENDS:=node/host
-PKG_NODE_VERSION:=8.10.0
+PKG_NODE_VERSION:=`$(STAGING_DIR_HOSTPKG)/bin/node --version`
 
 PKG_MAINTAINER:=John Crispin <blogic@openwrt.org>
 PKG_LICENSE:=Apache-2.0
@@ -67,8 +67,8 @@ EXTRA_LDFLAGS="-L$(TOOLCHAIN_DIR)/lib/ -Wl,-rpath-link $(TOOLCHAIN_DIR)/lib/" \
 define Build/Compile
 	$(MAKE_FLAGS) \
 	npm_config_arch=$(CONFIG_ARCH) \
-	npm_config_nodedir=$(BUILD_DIR)/node-v$(PKG_NODE_VERSION)/ \
-	npm_config_cache=$(BUILD_DIR)/node-v$(PKG_NODE_VERSION)/npm-cache \
+	npm_config_nodedir=$(BUILD_DIR)/node-$(PKG_NODE_VERSION)/ \
+	npm_config_cache=$(BUILD_DIR)/node-$(PKG_NODE_VERSION)/npm-cache \
 	PREFIX="$(PKG_INSTALL_DIR)/usr/" \
 	npm install -g $(PKG_BUILD_DIR)
 endef
@@ -91,6 +91,10 @@ endef
 define Package/node-cylon-firmata/install
 	mkdir -p $(1)/usr/lib/node/cylon-firmata
 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/node_modules/cylon-firmata/{index.js,lib,LICENSE,package.json,README.md,RELEASES.md,spec} $(1)/usr/lib/node/cylon-firmata/
+	# Strip PKG_BUILD_DIR from useless metadata inserted by npm install
+	# https://github.com/npm/npm/issues/10393
+	# https://github.com/npm/npm/issues/12110
+	find $(1)/usr/lib/node -name package.json -exec sed -i -e 's,$(PKG_BUILD_DIR),,g' {} +
 endef
 
 $(eval $(call BuildPackage,node-cylon))