In the last year I switched from macports/fink to brew; it has a lot of advantages. It also doesn’t ruin your system because it keeps it stuff inside /usr/local

But if you want to update a rather complex brew environment you’re in trouble. Some maintainers like the Riverwind guys only provide the last pyqt for download making it impossible to install an older version with homebrew. So in some cases it’s best to just completly remove the homebrew install and start over from scratch with the latest homebrew.

In most cases it wil output: /usr/local

Then reinstall it with the next command, or better yet ; copy it from the brew site again at https://github.com/mxcl/homebrew/wiki/installation: