Dev launcher is not installing the most recent snapshot

What I expected to happen was...:
I expected for the new Dev launcher (downloaded today) to properly install the newest snapshot.

What actually happened was...:
The console in the Dev launcher stalled for a little bit and spewed out the message in the attached picture.

Steps to Reproduce:
1. Open the most recent Dev launcher for OSX
2. Attempt to install on a fresh download of 1.5.2
3. Failure occurs

From logical deduction, I think I'm missing a library-- but after the lines "Support/minecraft/versions/13w19a/" I lose track of where its trying to tell me to go.