Output of `brew doctor`

output.txt

Warning: Setting DYLD_* vars can break dynamic linking.
Set variables:
    DYLD_FALLBACK_LIBRARY_PATH

Warning: "config" scripts exist outside your system or Homebrew directories.
`./configure` scripts often look for *-config scripts to determine if
software packages are installed, and what additional flags to use when
compiling and linking.

Having additional scripts in your path can confuse software installed via
Homebrew if the config script overrides a system or Homebrew provided
script of the same name. We found the following "config" scripts:

    /usr/local/opt/php53/bin/php-config
    /Users/william/.rbenv/shims/passenger-config

Warning: Your Xcode (4.3.3) is outdated
Please install Xcode 4.6.3.