[Red5] How do I resolve this dependency?

[Neill Jones]

Hello all,

I'm trying to build red5 using the instructions that I found on the wiki 
that basically say run
ant dist

I'm getting this error

   [taskdef] Could not load definitions from resource 
org/apache/ivy/ant/antlib.xml. It could not be found.

which I think is causing it to fail from then on.

Where do I get this file from? Where does it normally go? What is it 
used for? As you can tell I'm a newbie on this so really would 
appreciate any pointers.

Best regards

Neill