qt6 and Mint 18 Linux?

[Christian Ehrlicher]

Since we don't know what gcc and other deps your distribution provides, we can only point you to https://doc-snapshots.qt.io/qt6-dev/supported-platforms.html which tells you that at least gcc9 is needed.

[ofmrew]

The reason I asked is that the qt6 installation failed. Many have blamed the failure on a bad mirror. I can use C11 for qmake and it is the 64bit version of Mint, so I think it should work if I can get around the mirror problem. I installed qt6 on my Windows 10 computer with no trouble.

[SGaist]

Hi,

What exact failure do you have ?

[ofmrew]

@SGaist This a is a history I tried a few weeks ago: https://forum.qt.io/post/641169.

Now I just trying to get the download started, but it loads the unified file and stops. Is there a way with Linux to get an install without using chmod and sudo?

[SGaist]

Without chmod, no. Without sudo, yes, just select the single user option when you install and you'll have Qt installed in your home folder.

[ofmrew]

@SGaist Thank you. My Unix skills have been lost over the years, so thanks for the indulgence. I will try again to see if the mirror problem has been fixed.

[ofmrew]

@ofmrew Tried it again and same failure trying to download meta. Do you know it this problem is being worked on?

[SGaist]

AFAIK, it has already been fixed. Did you download the installer recently ? IIRC, there was an update not too long ago.

[ofmrew]

The installer was downloaded yesterday when I tried. Is there an URL that I should use. I seem to recall one posted but I do not know where.

[ofmrew]

@ofmrew To continue the last post, I tried again but the installer did not have the option to select a mirror site, so I am not sure that I have the correct installer.

[ofmrew]

@ofmrew I finally got to the correct installer but it failed with: qt6/6.0.1/gcc_64/bin/qmake -query is not parseable.

[ofmrew]

@ofmrew More info
[271035] Warning: Cannot get any query output from executable "/home/bobwilliams/Qt6/6.0.1/gcc_64/bin/qmake"
[272582] Warning: Cannot get any query output from qmake.
[293492] Warning: Cannot get any query output from qmake.
[584153] Warning: Cannot get any query output from qmake.
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Any suggestions?

[SGaist]

Run your application with QT_DEBUG_PLUGINS environment variable set to 1 to see what is going on.

[ofmrew]

@SGaist
I cannot run any application.
This is getting way beyond my Linux knowledge.

The statement: "Reinstalling the application may fix this problem." indicates that reinstalling might work. Should I try QT_DEBUG_PLUGINS=1? But how?

[SGaist]

Where are you starting your application from ?

[ofmrew]

@SGaist All of the "applications" you refer to were started from QtCreator. At first, I was learning Qt, then seeing that there was much confusion about 2D graphics, so I started writing a book and the "applications" were examples to be used in the book. When you use the term application I assume that you are referring to a program started from an icon or the command line. I have never created that kind of program in Qt.

The installation process was 91% complete when I got the error: qt6/6.0.1/gcc_64/bin/qmake -query is not parseable. Also in the Terminal I got:
[271035] Warning: Cannot get any query output from executable "/home/bobwilliams/Qt6/6.0.1/gcc_64/bin/qmake"
[272582] Warning: Cannot get any query output from qmake.
[293492] Warning: Cannot get any query output from qmake.
[584153] Warning: Cannot get any query output from qmake.
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Then I got the option to retry or ignore. I tried retry, but that did not work, so I tried ignore. It finished but QtCreator does not start execution.
I selected the option to accept the standard installation, maybe I should have tried the Custom Installation? Can I bypass "xcb" with the custom installation?

[ofmrew]

@ofmrew I tried a custom installation with only Qt6 and QtCreator and got to 60% before the same error message, but the Terminal showed:
bobwilliams@bobwilliamsLinux ~ $ cd /home/bobwilliams/Downloads
bobwilliams@bobwilliamsLinux ~/Downloads $ chmod +x qt-unified-linux-x64-4.0.1-1-online.run
bobwilliams@bobwilliamsLinux ~/Downloads $ ./qt-unified-linux-x64-4.0.1-1-online.run
QApplication: invalid style override passed, ignoring it.
Available styles: Windows, Fusion
[560115] Warning: Cannot get any query output from executable "/home/bobwilliams/Qt6.0/6.0.1/gcc_64/bin/qmake"
[561667] Warning: Cannot get any query output from qmake.

The Dialog also showed: Installing component Desktop gcc 64-bit and there is no Ignore option only Cancel.

What now?

[ofmrew]

@ofmrew FYI I tried the Qt6 Maintenance Tool and got the same error. It looks the problem is not just in the Installer.

What is my next step? Has anyone using Linux been successful with the installation process?

[ofmrew]

@ofmrew More info: It would appear that my glibc is at version 2.23 and at least 2.28 is required. What is the best way to upgrade glibc to the latest version? This is a known problem. Thanks.

[SGaist]

To have the complete error picture, you should add the QT_DEBUG_PLUGINS environment variable in the Run part of the Project panel.

As for updating glibc, you might want to consider updating your Mint version to an actual release.