Get it from http://developer.apple.com. You will not be able to submit apps to any stores using this XCode version, so turn away if that is something you might want to do.
In XCode's Preferences > Downloads you can install command line tools.
[insert screenshot]
sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
Visit http://xquartz.macosforge.org/trac/wiki and download and install 2.7.2+.
You will need to fix the symlink it makes:
ln -s /opt/X11 /usr/X11
brew list
Will tell you what you need to check. Try out everything one by one and when one doesn't work brew remove it and then reinstall it. If the install doesn't work, try brew install it --use-gcc to prevent llvm from getting in the way.
Things that gave me issues that I had to remove and install:
- macvim
- imagemagick
- ghostscript
You might need to install libxml2 and link it manually to make sure you don't get the wrong xml2-config if your path:
$ brew install libxml2 $ brew link libxml2
cd /usr/bin && sudo ln -s llvm-gcc-4.2 gcc-4.2
I was able to get things working by just installing "Command Line Tools 10.8 for Xcode - Late July 2012" (not XCode itself) from:
https://developer.apple.com/downloads/index.action
(Follow the "View all downloads" link from the Mac Dev Center page)
FYI, I did not have XCode installed on Lion, just the "Command Line Tools". Not sure if the new XCode command line tools will play nice with the old XCode.