revamp the handbook make targets

Handbook/GNUmakefile

@@ -224,7 +224,7 @@ help:
 .PHONY: info
 info:
 	@echo ""
-	@echo "Building $(SG_PROJECT_NAME)..."
+	@echo "$(SG_PROJECT_NAME) build information:"
 	@echo ""
 	@echo "  - Handbook Revision     :  $(SG_HANDBOOK_REVISION)"
 	@echo "  - Git Branch            :  $(SG_GIT_BRANCH)"
@@ -311,7 +311,26 @@ endif # ($(SG_HANDBOOK_REVISION), next)
 serve: info
 serve: install-build-deps
 serve: prepare
-serve:
+serve: _mdbook_serve
+
+.PHONY: build
+build: info
+build: install-build-deps
+build: prepare
+build: verify-handbook-revision
+build: _mdbook_build
+
+.PHONY: deploy
+deploy: info
+deploy: install-build-deps
+deploy: clean
+deploy: prepare
+deploy: verify-handbook-revision
+deploy: _mdbook_build
+deploy:
+
+.PHONY: _mdbook_serve
+_mdbook_serve:
 	@echo "Serving $(SG_HANDBOOK_DIR)..."
 	@env SG_PROJECT_NAME='$(SG_PROJECT_NAME)' \
 		SG_HANDBOOK_REVISION='$(SG_HANDBOOK_REVISION)' \
@@ -337,14 +356,26 @@ serve:
 				--watcher $(SG_MDBOOK_WATCHER) \
 				--dest-dir $(SG_MDBOOK_DEST_DIR)
 
-.PHONY: build
-build: info
-build: install-build-deps
-build: prepare
-build: verify-handbook-revision
-build:
-
-.PHONY: deploy
-deploy: clean
-deploy: build
-deploy:
+.PHONY: _mdbook_build
+_mdbook_build:
+	@echo "Building $(SG_HANDBOOK_DIR)..."
+	@env SG_PROJECT_NAME='$(SG_PROJECT_NAME)' \
+		SG_HANDBOOK_REVISION='$(SG_HANDBOOK_REVISION)' \
+		SG_GIT_BRANCH='$(SG_GIT_BRANCH)' \
+		SG_GIT_TAG='$(SG_GIT_TAG)' \
+		SG_GIT_COMMIT='$(SG_GIT_COMMIT)' \
+		SG_GIT_COMMIT_NUMS_SINCE_TAG='$(SG_GIT_COMMIT_NUMS_SINCE_TAG)' \
+		SG_GIT_TREE_STATE='$(SG_GIT_TREE_STATE)' \
+		SG_GIT_VERSION='$(SG_GIT_VERSION)' \
+		SG_GIT_VERSION_MAJOR='$(SG_GIT_VERSION_MAJOR)' \
+		SG_GIT_VERSION_MINOR='$(SG_GIT_VERSION_MINOR)' \
+		SG_GIT_VERSION_PATCH='$(SG_GIT_VERSION_PATCH)' \
+		SG_PLUGIN_VERSION='$(SG_PLUGIN_VERSION)' \
+		SG_PLUGIN_VERSION_MAJOR='$(SG_PLUGIN_VERSION_MAJOR)' \
+		SG_PLUGIN_VERSION_MINOR='$(SG_PLUGIN_VERSION_MINOR)' \
+		SG_PLUGIN_VERSION_PATCH='$(SG_PLUGIN_VERSION_PATCH)' \
+		SG_BUILD_HOST='$(SG_BUILD_HOST)' \
+		SG_BUILD_TIME='$(SG_BUILD_TIME)' \
+		MDBOOK_output__pdf__browser_binary_path='$(SG_MDBOOK_PDF_BROWSER_BINARY_PATH)' \
+			mdbook build \
+				--dest-dir $(SG_MDBOOK_DEST_DIR)