prezto: Sorin theme causes shell to hang.

My shell gets into a state where I can’t do anything, I have to close the window and open a new shell. If I just hold ^C, this is my output:

~ ❯❯❯
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
~ ❯❯❯                                                                         ⏎
^C^C^C^C^C^C^C^C^C^C^C^C^C

At the end, you can see that the shell is busted, there is no way to get out.

Any help debugging/fixing would be much appreciated.

• OSX 10.10.3
• github.com/breerly/dotfiles
• prezto - https://github.com/sorin-ionescu/prezto/tree/a275db55d6fdc8bf92a4722e95196bbfbf44cfae