Migrating Qt 5.5.1 -> Qt 5.6.0 .. how to avoid multiple versions?



  • I had previously installed and tested Qt 5.5.1 on Ubuntu 14.04 (32 bit).
    from the PPA repository here ...
    https://launchpad.net/~beineri/+archive/ubuntu/opt-qt551-trusty
    into /opt/qt55

    I then installed Qt 5.6.0 from same PPA repository ...
    https://launchpad.net/~beineri/+archive/ubuntu/opt-qt56-trusty
    into /opt/qt56
    alongside /opt/qt55

    Now when I launch Qt 5.6 Creator and view > Options > Build & Run > Qt Versions

    I see ...

    Auto-detected
    Qt 5.5.1 in PATH (qt55) /opt/qt55/bin/qmake

    Manual
    Qt 5.6.0 (qt56) /opt/qt56/bin/qmake

    ...

    When in Qt Creator 3.6.1 (based on Qt 5.6.0) and starting a new simple widget project

    then Ctrl+K .. the Custom Commands pop-up list refers to /opt/qt55 and not as I expect /opt/qt56

    ...
    Running qmake --version
    returns ..
    QMake version 3.0
    Using Qt version 5.6.0 in /opt/qt56/lib
    ...

    Because of this confusion between qt55 and qt56 installations I would prefer to uninstall/purge Qt 5.5.1.

    But when I tried that (by admittedly crude method of temporary disabling installation folder /opt/qt55 by renaming to /opt/__qt55 to break paths) I found that the Auto-detected entry in Qt Creator then showed an error under Auto-detected.

    I had to re-enable /opt/qt55 to remove the error in Qt Creator.

    Surely the Auto-detected and Manual variables should be identical?

    My question is .. what is best practice to safely purge Qt 5.5.1 from /opt/qt55 to leave only Qt 5.6.0 installed in /opt/qt56? And for the Auto-detect to find only 5.6.0?

    ...

    There is a related thread found here ...
    https://forum.qt.io/topic/65394/how-to-completely-un-install-qt
    but I prefer not to have multiple versions of Qt.


  • Moderators



  • @JKSH
    Thanks for the link.

    I have Y PPA Manager already installed so I can use that tool to remove/purge both PPA installations to allow me to start with a clean sheet to reinstall Qt 5.6.0 (32 bit Linux) from Qt downloads site.

    However I cannot find an installer for 32bit Qt 5.6.0 .. http://www.qt.io/download-open-source/

    There are offline installers but only for Linux 64 bit.
    I don't want to go through a build from source.

    So I have to return to the option of using PPA pre-built versions.
    I'll try purging Qt 5.5.1.

    Why doesn't Qt place a Linux 32bit offline installer on the Qt downloads page (as you do for Windows)?


  • Moderators

    @eureka said:

    Why doesn't Qt place a Linux 32bit offline installer on the Qt downloads page (as you do for Windows)?

    It's a decision made by the Qt release team: http://comments.gmane.org/gmane.comp.lib.qt.devel/22021 Qt 5.5.1 is the last version of Qt that will receive a pre-built 32-bit package on Linux. I'm guessing it's because the market share of 32-bit desktop Linux is diminishing.

    Each pre-built package costs time and energy to test, so not all possibilities can be supported, unfortunately. For example, MinGW users on Windows are stuck with 32-bit installers only; there's no 64-bit MinGW installer.



  • @JKSH said:

    I'm guessing it's because the market share of 32-bit desktop Linux is diminishing.

    Unfortunately I'll have to live with my ancient laptop (x86) for some time yet, so I returned to the PPA pre-built 32bit route.

    After uninstalling Qt 5.5.1 and Qt 5.6.0 and then reinstalling only Qt 5.6.0 I was back where I started with references to /opt/qt55 still seen (as I wrote above in my first post).

    I realised that I had to disable ~/.config/QtProject folder which held historical data referring to /opt/qt55. A fresh Qt folder was auto created in ~/.config when I loaded Qt 5.6 Creator.

    I kept a backup of the old ~/.config/QtProject folder in case I need to refer back to contents.

    So on now to trying Qt 5.6.0 app development.

    Thanks.


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.