How do I check for ldconfig in a makefile?

This makefile errors because it tries to run ldconfig, even though OS = Darwin and I have no idea why
Code:
ifeq ($(SHARED),1)
install: banner install_headers $(lib_target)
	@echo "Install shared library"
	cp -f ./$(lib_target) $(inst_path)
	cd $(inst_path) ; \
	ln -sf $(lib_target) $(libname_shared_major_version) ; \
	ln -sf $(libname_shared_major_version) $(libname_shared)
	ifneq ($(OS),Darwin)
		ldconfig
	endif
	@echo "Install shared library: Done."
else
install: banner install_headers $(lib_target)
	@echo "Install static library"
	cp -f ./$(lib_target) $(inst_path)
	@echo "Install static library: Done."
endif
Errors
Code:
/bin/sh: -c: line 0: syntax error near unexpected token `Darwin,Darwin'
/bin/sh: -c: line 0: `ifneq (Darwin,Darwin)'
make: *** [install] Error 2
make: ldconfig: No such file or directory
make: *** [uninstall] Error 1