本机安装了qt4 和qt5; 通过修改qt-default/qtchooser/default.conf 可以修改默认qt版本
[email protected]:/usr/lib/x86_64-linux-gnu$ ls qt
qt4/ qt5/ qtchooser/ qt-default/
[email protected]:/usr/lib/x86_64-linux-gnu$ cat qt-default/qtchooser/default.conf
/usr/lib/x86_64-linux-gnu/qt5/bin
/usr/lib/x86_64-linux-gnu
[email protected]:/usr/lib/x86_64-linux-gnu$ qmake -v
QMake version 3.0
Using Qt version 5.5.1 in /usr/lib/x86_64-linux-gnu
[email protected]:/usr/lib/x86_64-linux-gnu$ sudo vi qt-default/qtchooser/default.conf
[sudo] password for zhangym:
[email protected]:/usr/lib/x86_64-linux-gnu$ qmake -v
QMake version 2.01a
Using Qt version 4.8.7 in /usr/lib/x86_64-linux-gnu
[email protected]:/usr/lib/x86_64-linux-gnu$