qtchooser 39-g4717841-3 (amd64 binary) in ubuntu trusty

 Qt is a cross-platform C++ application framework. Qt's primary feature
 is its rich set of widgets that provide standard GUI functionality.
 .
 The Qt Chooser provides a wrapper to switch between versions of Qt
 development binaries when multiple versions like 4 and 5 are installed
 or local Qt builds are to be used.
 .
 If you wish to use Qt development binaries with the default PATH and
 without special parameters, you need to additionally install either
 qt4-default or qt5-default package to provide the default configuration.