Step 13 - port-lib-depends-check The package tools need some assistance to build the dependency chain of a package. That means we have to record the dependencies in the Makefile. Fortunately, there is a nice make(1) target to help us with this task. $ make port-lib-depends-check iodine-0.4.0: WANTLIB: c.42 (/usr/local/sbin/iodined) (system lib) WANTLIB: z.4 (/usr/local/sbin/iodined) (system lib) WANTLIB += c z *** Error code 1 (ignored) $ As we can see, iodine depends on two libraries from the base system. The last line before the Error shows us what needs to be added to the Makefile.