github: add check-gh-conf targets to verify updates and downloads

Makefile

@@ -488,6 +488,7 @@ download-only-$(1): download-only-$($(1)_FILE)
 download-only-$($(1)_FILE)::
 	$(and $($(1)_URL),
 	@[ -d '$(LOG_DIR)/$(TIMESTAMP)' ] || mkdir -p '$(LOG_DIR)/$(TIMESTAMP)'
+	@$$(if $$(REMOVE_DOWNLOAD),rm -f '$(PKG_DIR)/$($(1)_FILE)')
 	@if ! $(call CHECK_PKG_ARCHIVE,$(1)); then \
 	    $(PRINTF_FMT) '[download]' '$(1)' | $(RTRIM); \
 	    (set -x; $(call DOWNLOAD_PKG_ARCHIVE,$(1))) &> '$(LOG_DIR)/$(TIMESTAMP)/$(1)-download'; \
@@ -506,8 +507,14 @@ download-only-$($(1)_FILE)::
 	        exit 1; \
 	    fi; \
 	fi)
+
+.PHONY: prepare-pkg-source-$(1)
+prepare-pkg-source-$(1): download-only-$(1)
+	rm -rf '$(2)'
+	mkdir -p '$(2)'
+	$$(call PREPARE_PKG_SOURCE,$(1),$(2))
 endef
-$(foreach PKG,$(PKGS),$(eval $(call PKG_RULE,$(PKG))))
+$(foreach PKG,$(PKGS),$(eval $(call PKG_RULE,$(PKG),$(call TMP_DIR,$(PKG)))))
 
 # disable networking during build-only rules for reproducibility
 ifeq ($(findstring darwin,$(BUILD)),)

github.mk

@@ -114,3 +114,24 @@ define MXE_GET_GH_TAG
     | $(SORT) -V
     | tail -1
 endef
+
+GITHUB_PKGS = $(patsubst %_GH_CONF,%,$(filter %_GH_CONF,$(.VARIABLES)))
+
+# check-gh-conf   : test updates and source directory
+# check-gh-conf-dl: removes downloads and tests above
+
+# a test of many package updates may hit rate limit of 60/hr
+# https://developer.github.com/v3/#rate-limiting
+
+.PHONY: check-gh-conf check-gh-conf-%
+check-gh-conf-dl: REMOVE_DOWNLOAD = true
+check-gh-conf-dl: MXE_NO_BACKUP_DL = true
+check-gh-conf-dl: check-gh-conf
+check-gh-conf-pkg-%: check-update-package-% download-only-%
+	@$(PRINTF_FMT) '[prep-src]'  '$(*)' | $(RTRIM)
+	@($(MAKE) -f '$(MAKEFILE)' 'prepare-pkg-source-$(*)') > /dev/null
+	@rm -rf '$(call TMP_DIR,$(*))'
+
+# secondexpansion here since this file is included before pkg makefiles
+.SECONDEXPANSION:
+check-gh-conf: $$(addprefix check-gh-conf-pkg-,$$(GITHUB_PKGS))