Last login: Thu May 19 03:54:50 on ttys000
Yanskys-MacBook-Pro:~ yansky$ brew doctor
We couldn't detect gcc 4.0.x. Some formulae require this compiler.

/usr/bin is in your PATH before Homebrew's bin. This means that system-
provided programs will be used before Homebrew-provided ones. This is an
issue if you install, for instance, Python.

Consider editing your .bashrc to put:
  /usr/local/bin
ahead of /usr/bin in your $PATH.

Some brews install binaries to sbin instead of bin, but Homebrew's
sbin was not found in your path.

Consider editing your .bashrc to add:
  /usr/local/sbin
to $PATH.

You have a non-brew 'pkg-config' in your PATH:
  /usr/bin/pkg-config

`./configure` may have problems finding brew-installed packages using
this other pkg-config.

Your pkg-config is not checking "/usr/X11/lib/pkgconfig" for packages.
Earlier versions of the pkg-config formula did not add this path
to the search path, which means that other formula may not be able
to find certain dependencies.

To resolve this issue, re-brew pkg-config with:
  brew rm pkg-config && brew install pkg-config

/Library/Frameworks/Mono.framework detected

This can be picked up by Cmake's build system and likey cause the
build to fail, finding improper header files for libpng for instance.

Yanskys-MacBook-Pro:~ yansky$