When opening the launcher, it seemed to run rather slow and then when it tried to launch the game, it stopped appearing to do anything, leaving the launcher log and the game log tabs both blank. Upon running the game through the terminal, it was found to be an IllegalArgumentException preventing the game from launching.
I am somewhat uncertain about the steps to reproduce, but I started from a clean install of Minecraft, without any data files to provide as detailed of a log as I could. Through guidance at the IRC support, I've gone through many attempts to fix it, but the same bug has still persisted. Feel free to ask anything you need to about the environment, I'll answer asap.