Ubuntu Qmake is not an executable

Question

after installing new version of QtCreator in Ubuntu and

tux-world@alachiq:~ > sudo apt-get install qt5-qmake build-essential g++ gcc
   Reading package lists... Done
   Building dependency tree       
   Reading state information... Done
   build-essential is already the newest version.
   g++ is already the newest version.
   g++ set to manually installed.
   gcc is already the newest version.
   qt5-qmake is already the newest version.
   0 upgraded, 0 newly installed, 0 to remove and 247 not upgraded.

in option of Build & Run and choose qmake in /usr/bin/qmake i get this error :

The qmake executable /usr/lib/i386-linux-gnu/qt4/bin/qmake could not be added: qmake '/usr/lib/i386-linux-gnu/qt4/bin/qmake' is not an executable.

in Home system i don't have any problem after installing those packages and setting Qmake in option

Other information:

tux-world@alachiq:~ > apt-cache search qt5-qmake
qt5-qmake - Qt 5 qmake Makefile generator tool

tux-world@alachiq:~ > ldd /opt/qtForArm/bin/qmake 
     ldd: /opt/qtForArm/bin/qmake: No such file or directory

tux-world@alachiq:~ > sudo chmod +x /usr/lib/i386-linux-gnu/qt4/bin/qmake
[sudo] password for tux-world: 
chmod: cannot access ‘/usr/lib/i386-linux-gnu/qt4/bin/qmake’: No such file or directory

UPDATE:

tux-world@alachiq:~ > apt-cache policy qt5-qmake
qt5-qmake:
  Installed: 5.2.1+dfsg-1ubuntu14.2
  Candidate: 5.2.1+dfsg-1ubuntu14.2
  Version table:
 *** 5.2.1+dfsg-1ubuntu14.2 0
        500 http://archive.ubuntu.com/ubuntu/ trusty-updates/main i386 Packages
        100 /var/lib/dpkg/status
     5.2.1+dfsg-1ubuntu14 0
        500 http://archive.ubuntu.com/ubuntu/ trusty/main i386 Packages



tux-world@alachiq:~ > ls -a -l /usr/bin/qmake 
lrwxrwxrwx 1 root root 9 فوریه 19 15:53 /usr/bin/qmake -> qtchooser



tux-world@alachiq:~ > qtchooser 
Usage:
  qtchooser { -l | -list-versions | -print-env }
  qtchooser -run-tool=<tool name> [-qt=<Qt version>] [program arguments]
  <executable name> [-qt=<Qt version>] [program arguments]

Environment variables accepted:
 QTCHOOSER_RUNTOOL  name of the tool to be run (same as the -run-tool argument)
 QT_SELECT          version of Qt to be run (same as the -qt argument)

tux-world@alachiq:~ > 

Answer 1

You have installed qt5-qmake, but your Qt Creator is looking for the Qt4 version of qmake. You can either install qt4-qmake or add your Qt5 qmake executable to Qt Creator in Tools -> Options -> Build & Run -> Qt Versions.

/edit after an update in the question:

Qt Chooser is a tool to automatically select the correct Qt binaries depending on its configuration and/or environment variables.

If you want to use the Qt 5 qmake, all you need to is installing the package qt5-default. That will point the various binaries (like /usr/bin/qmake) provided by Qt Chooser to your Qt 5 installation. If you want to use the Qt 4 qmake, you'll need to install qt4-default, which does the same thing, but for Qt 4.