Right after the unexec phase I get:

> make -C ./nextstep all
> make: *** ./nextstep: No such file or directory.  Stop.
> make[1]: *** [ns-app] Error 2
> make: *** [src] Error 2

The attached patch fixes the issue for me.

Weirdly, the error only shows up on one of my computers: one with a very
clean install of 10.9—my main 10.9 machine (lots of assorted Homebrew
stuff installed) works just fine.

I first noticed the problem on the 15th. Looks like a typo in revision
117337.

-David