refactor(make): organize preparation directives

Makefile

@@ -43,19 +43,17 @@ SPHINX_CONF := $(CPYTHON_CLONE)/Doc/conf.py
 LANGUAGE := zh_TW
 LC_MESSAGES := $(CPYTHON_CLONE)/Doc/locales/$(LANGUAGE)/LC_MESSAGES
 VENV := ~/.venvs/python-docs-i18n/
-PYTHON := $(shell which python3)
 MODE := autobuild-dev-html
 JOBS := 4
 
 .PHONY: all
-all: $(VENV)/bin/sphinx-build $(VENV)/bin/blurb clone ## Automatically build an html local version
-	mkdir -p $(LC_MESSAGES)
+all: prepare_deps ## Automatically build an html local version
 	for dirname in $$(find . -name '*.po' | xargs -n1 dirname | sort -u | grep -v '^\.$$'); do mkdir -p $(LC_MESSAGES)/$$dirname; done
 	for file in *.po */*.po; do ln -f $$file $(LC_MESSAGES)/$$file; done
 	. $(VENV)/bin/activate; $(MAKE) -C $(CPYTHON_CLONE)/Doc/ SPHINXOPTS='-j$(JOBS) -D locale_dirs=locales -D language=$(LANGUAGE) -D gettext_compact=0' $(MODE)
 
 .PHONY: build
-build: $(VENV)/bin/sphinx-build $(VENV)/bin/blurb clone ## Automatically build an html local version for a single file
+build: prepare_deps ## Automatically build an html local version for a single file
 	@$(eval target=$(filter-out $@,$(MAKECMDGOALS)))
 	@if [ -z $(target) ]; then \
 		echo "\x1B[1;31m""Please provide a file argument.""\x1B[m"; \
@@ -80,15 +78,18 @@ build: $(VENV)/bin/sphinx-build $(VENV)/bin/blurb clone ## Automatically build a
 help:
 	@python3 -c "$$PRINT_HELP_PYSCRIPT" < $(MAKEFILE_LIST)
 
-clone: ## Clone latest cpython repository to `../cpython/` if it doesn't exist
+.PHONY: prepare_deps
+prepare_deps: $(VENV)/bin/sphinx-build $(VENV)/bin/blurb upgrade_venv prepare_cpython  ## Prepare dependencies
+
+.PHONY: prepare_cpython
+prepare_cpython:  ## Prepare CPython clone at `../cpython/`.
 	git clone --depth 1 --no-single-branch https://github.com/python/cpython.git $(CPYTHON_CLONE)  || echo "cpython exists"
-	cd $(CPYTHON_CLONE) && git checkout $(VERSION)
+	cd $(CPYTHON_CLONE) && git checkout $(VERSION) && git pull origin $(VERSION)
+	mkdir -p $(LC_MESSAGES)
 
 
 $(VENV)/bin/activate:
-	mkdir -p $(VENV)
-	$(PYTHON) -m venv $(VENV)
-
+	python3 -m venv $(VENV)
 
 $(VENV)/bin/sphinx-build: $(VENV)/bin/activate
 	. $(VENV)/bin/activate; python3 -m pip install sphinx python-docs-theme
@@ -102,7 +103,7 @@ $(VENV)/bin/blurb: $(VENV)/bin/activate
 
 .PHONY: upgrade_venv
 upgrade_venv: $(VENV)/bin/activate ## Upgrade the venv that compiles the doc
-	. $(VENV)/bin/activate; python3 -m pip install --upgrade sphinx python-docs-theme blurb sphinx-lint
+	@. $(VENV)/bin/activate; python3 -m pip install -q --upgrade sphinx python-docs-theme blurb sphinx-lint
 
 
 .PHONY: progress
@@ -118,7 +119,7 @@ todo: ## List remaining tasks
 
 
 .PHONY: merge
-merge: upgrade_venv ## To merge pot from upstream
+merge: prepare_deps  ## To merge pot from upstream
 	(cd $(CPYTHON_CLONE)/Doc; rm -f build/NEWS)
 	(cd $(CPYTHON_CLONE)/Doc; $(VENV)/bin/sphinx-build -Q -b gettext -D gettext_compact=0 . locales/pot/)
 	find $(CPYTHON_CLONE)/Doc/locales/pot/ -name '*.pot' |\