Ecco il mio comando e output (alcuni argomenti della riga di comando sono esclusi):
$ brew reinstall pyqt --with-python3
==> Reinstalling pyqt --with-python3
==> Downloading http://downloads.sf.net/project/pyqt/PyQt4/PyQt-4.10.3/PyQt-mac-
Already downloaded: /Library/Caches/Homebrew/pyqt-4.10.3.tar.gz
==> Patching
patching file configure.py
==> python configure.py --confirm-license --bindir=/usr/local/Cellar/pyqt/4.10.3
==> python ./configure-ng.py --confirm-license --bindir=/usr/local/Cellar/pyqt/4
==> make
==> make install
==> Caveats
Set PYTHONPATH if you want Python to find your site-packages:
export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH
==> Summary