I hope you weren't holding your breath waiting for an answer. I just ran into this, from xtext, rather than Acceleo. If you watch the directory where the build.xml is created (and quickly deleted), you may be able to capture a copy, as I did. But the problem is in the log you have:
Problem: failed to create task or type apitooling.apigeneration
Googling for this, you'll come to the conclusion that you need to install some part or parts of the Eclipse PDE (Plug-in Development Environment). Because your eclipse deployment could be in any of a near-infinite set of states, that's about all I can say! In my case, I just installed the whole PDE, from the Kepler update site (http://download.eclipse.org/releases/kepler/). You might snoop around in your installed plugins to see if you already have some installed components (org.eclipse.pde.*), in which case I think you will want to try to download a version that's at or slightly above that version. In my case, I had some 3.8.1 installed, and I installed the entire 3.9.1 PDE. As always, if you have a lot invested in your current Eclipse package, consider backing it up first.
I'm new in this, and only have limited experience to advise from!