How to install Cairo using Homebrew on Lion?

I am trying to install Cairo using Homebrew on Mac OS X Lion, but I get the following error:

Undefined symbols for architecture x86_64:
  "_png_set_longjmp_fn", referenced from:
      _read_png in cairo-png.o
      _png_simple_error_callback in cairo-png.o
      _write_png in cairo-png.o
ld: symbol(s) not found for architecture x86_64
collect2: ld returned 1 exit status
make[3]: *** [libcairo.la] Error 1

I thought it might be that libpng wa开发者_Python百科s missing, and it's included with X11 in Lion, so I added ENV.x11 to Cairo's formula, this didn't fix it.

What's the next place I should look? Should I post more of the error/log?

I reinstalled libpng using this package: http://ethan.tira-thompson.com/Mac_OS_X_Ports.html, that solved the problem.