I'm not certain that this is what fixed the problem, but after looking through the README's I did (on Ubunutu) "sudo apt-get install astyle" and then the recompile worked. I'm pretty sure that the check at the beginning of the Forge installation said that it found astyle even before I installed, although apt-get definitely acted like it was not already installed. Curious if someone familiar with what astyle is used for can confirm/deny that this could have been related to the issue that I was seeing.