title: How to install Cairo using Homebrew on Lion?
body: <p>I am trying to install <strong>Cairo</strong> using <strong>Homebrew</strong> on Mac OS X Lion, but I get the following error:</p>
  
  <pre><code>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
  </code></pre>
  
  <p>I thought it might be that libpng was missing, and it's included with X11 in Lion, so I added <code>ENV.x11</code> to Cairo's formula, this didn't fix it.</p>
  
  <p>What's the next place I should look? Should I post more of the error/log? </p>