qt4 replaces qt
A new qt4 package is in [extra]. This replaces the current qt package.
All packages depending on qt need to be rebuilt to depend on qt4. We have done this for all official packages, but you will need to rebuild packages installed from the AUR that depend on qt.
To know which package need to be rebuild you can use pkgtools
After installation (#pacman -S pkgtools) do
As the official packages are rebuild for you, you only have to rebuild the AUR packages.
For me it means I have to rebuild: cdcat fontmatrix qbittorrent sir syncbackup.
This is an example why pacman is so fantastic:
:: Replace qt with extra/qt4? [Y/n] y
looking for inter-conflicts...
error: failed to prepare transaction (could not satisfy dependencies)
:: cdcat: requires qt
:: fontmatrix: requires qt>=4.3.0
:: qbittorrent: requires qt
:: sir: requires qt
:: syncbackup: requires qt