Using namespace for your Flex library swc

I downloaded degrafa today, and built the swc from source. I wanted to use the library like so in my MXML file:

First time when I built it, I got an error trying it the above way.
Read up on the doc, and this time I included the Namespace URL and Manifest file path in Project Properties->Flex Library Compiler.
Tried it again and still no go, got some dumb "Could not resolve x to component implementation" error.
Read up the doc one more time on the compiler option one more time, this time I included another parameter -include-namespaces and rebuilt the project, and it worked.