I still cannot write Makefiles it seems

Makefile

@@ -201,13 +201,13 @@ gadagne_restart: gadagne
 release:
 	echo "current version: " && grep '^version' about.pl
 	@read -p "Version number (e.g. 4.1.0): " version && \
-	git flow release start '$$version' && \
+	git flow release start "$$version" && \
 	sed -i'' -e "s/^version('.*')/version('$$version')/" about.pl && \
 	sed -i'' -e "s/\"version\": \"\(.*\)\"/\"version\": \"$$version\"/" biocham_jupyter/guinbextension/package.json && \
 	sed -i'' -e "s/__version__ = '\(.*\)'/__version__ = '$$version'/" biocham_jupyter/kernel/biocham_kernel/__init__.py && \
 	LC_ALL=C sed -i'' -e "s+^<h1>version.*</h1>+<h1>version $$version $(shell date '+%B %Y')</h1>+" web/index.html && \
 	git commit about.pl biocham_jupyter/guinbextension/package.json biocham_jupyter/kernel/biocham_kernel/__init__.py web/index.html -m "Version $$version" && \
-	git flow release finish '$$version' && \
+	git flow release finish "$$version" && \
 	git push --tags
 
 refs: $(NOTEBOOKS) biocham