Missing directory during container build.

singularity/workflows_base.def

@@ -25,6 +25,7 @@ Stage: build-haskell
 	do
 	    (cd ${dir} && grep "local" install.sh && ./install.sh)
 	done
+	mkdir -p /usr/local/share/doc
 	echo "# Haskell tools" >> /usr/local/share/doc/program_versions.txt
 	echo "${HASKELL_TOOLS_VERSION}" >> /usr/local/share/doc/program_versions.txt