avoid unnecessary work in 'make build'

Makefile

@@ -145,9 +145,10 @@ clean: clean-dist
 		$(SUBMAKE) -C $$dir clean; \
 	done
 
+# remove any files in dist/ folder without current build hash
 .PHONY: clean-dist
-clean-dist:
-	rm -rf dist
+clean-dist: buildhash
+	find dist \! -name "*$$(cat meta/buildhash)*" -type f -delete
 
 .PHONY: check
 check: pyenv buildhash prepare
@@ -181,7 +182,7 @@ add-buildhash:
 	fi; \
 	ver="$$(cat meta/version)"; \
 	hash="$$(cat meta/buildhash)"; \
-	${RENAME_BIN} "s/-$${ver}(\.|-)/-$${ver}+$${hash}\$$1/" dist/*-"$${ver}"*
+	${RENAME_BIN} -f "s/-$${ver}(\.|-)/-$${ver}+$${hash}\$$1/" dist/*-"$${ver}"*
 
 
 .PHONY: pull-i18n

pylib/Makefile

@@ -99,10 +99,13 @@ CHECKDEPS := $(shell ${FIND} anki tests -name '*.py' | grep -v buildinfo.py)
 ######################
 
 .PHONY: build
-build: $(BUILD_STEPS) $(CHECKDEPS)
+build: .build/build
+
+.build/build: $(BUILD_STEPS) $(CHECKDEPS)
 	rm -rf dist build
 	python setup.py -q bdist_wheel
 	rsync -a dist/*.whl ../dist/
+	touch $@
 
 # prepare code for running in place
 .PHONY: develop

qt/Makefile

@@ -127,10 +127,13 @@ CHECKDEPS := $(shell ${FIND} aqt tests -name '*.py' | grep -v buildinfo.py)
 ######################
 
 .PHONY: build
-build: $(BUILD_STEPS)
+build: .build/build
+
+.build/build: $(BUILD_STEPS) $(CHECKDEPS)
 	rm -rf dist build
 	python setup.py -q bdist_wheel
 	rsync -a dist/*.whl ../dist/
+	touch $@
 
 .PHONY: develop
 develop: $(BUILD_STEPS)

rspy/Makefile

@@ -60,11 +60,13 @@ DEPS := .build/tools .build/vernum ../meta/buildhash \
 		CARGO_TARGET_DIR="$(RSPY_TARGET_DIR)" maturin develop $(DEVFLAGS)
 	touch $@
 
-build: $(DEPS)
-	rm -rf "$(OUTDIR)"/ankirspy*
+build: .build/build
+
+.build/build: $(DEPS)
 	touch ../proto/backend.proto
 	FTL_TEMPLATE_DIRS="$(QT_FTL_TEMPLATES)" FTL_LOCALE_DIRS="$(QT_FTL_LOCALES)" \
 		maturin build -i "${PYTHON_FILE}" -o "$(OUTDIR)" $(BUILDFLAGS)
+	touch $@
 
 check: .build/check