Go to terminal and roll back the Qt installation through GitHub
$ brew uninstall qt
$ brew install https://raw.githubusercontent.com/Homebrew/homebrew/8dd3478131b232553f4c0cab197f8443a0a559a6/Library/Formula/qt.rb
Pin your Qt install (this should keep brew upgrade
from upgrading it)
$ brew pin qt
All done until another upgrade breaks something :)