problem with qt library

[finit12]

hi ,i run many applications Almost all errors are these two :/

qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in ""
This application failed to start because no Qt platform plugin could be initialized.

or

Cannot mix incompatible Qt library (5.12.9) with this library (5.15.0)

and i trying to fix this but some app They failed after install qt , any stable qt5.15 or newer for for bionicpup64 If it is available please give me thank u

[mikewalsh]

That error sounds like you have more than one version of Qt5 installed. Qt is very fussy about such things, and will complain like a bitch if you do this.

3 questions:-

• How did you install Qt5?

• Where did you get it from?

• Are you attempting to run something like an AppImage, or a self-contained portable of some kind which has its own Qt version built-in?

The more information you can give us, the greater the chances of our being able to help. We're NOT mind-readers..!

Mike.

[finit12]

no im not install qt library but i use lxqt desktop environment

and i open krita appimage and utopia p2p in puppy jwm with no save file They make the same error

[finit12]

nobody know

[666philb]

hi @finit12 ,

krita is in quickpet so use that version.
as for utopia maybe try to find an older version

[finit12]

thanks for answering can i clean all qt and install again?

[bigpup]

What exact version of Bionic are you using?
How exactly is it installed? Full, frugal, and on what storage device???

What exact QT did you install and exactly how????

Did you do the QT install before or after you got these error messages?

[mikeslr]

Hi finit12

Do follow 666philb suggestions. An alternative with respect to krita is discussed here. viewtopic.php?p=10579#p10579. My work-around resulting from the QT problem is the 2nd post to that thread.

Regarding Utopia p2p, out of curiosity I downloaded and Right-Clicked>UExtracted the debian/Ubuntu deb offered by the website. Right-Click>ListDD (list dynamic dependencies) on the utopia binary --it's buried in /opt/utopia/messenger. That showed that, among others, libQt5Core.so.5 (Qt_5.13) was missing. I'm not sure if even fossa focal/fossapup is using a version of Qt5 that new*.

A fairly exhaustive search failed to reveal any source for old versions; indeed, any source other than via utopia's website. Best bet for obtaining a missing library is to install pkg-cli, learn how to add repositories and find out which distro's repo has it. Not having any old versions floating around may be a good security protocol, but I think it violates 'open source' requirements.

Having spent 30 years 'looking gift horses in the mouth', that's one red flag. Another is its involvement with cryto-currencies combined with the incentive to use them and the disclaimer that it won't hurt. I think you can accomplish most of Utopia's claimed benefits are by running tor under a vpn. Encrypt files before transmitting and you're using an encrypted transmission to send a differently encrypted file from an undisclosed location. And there are other ways to mask one's location.

0-0-0-0-0-0
* Edit: This morning I booted into FossaPup64 and remembered this question. Ubuntu Fossa Focal/Fossapup64's libQt5s are the .12 builds. Examining the links from pkgs.org, Ubuntu Groovy Gorilla uses .14 builds. Debian Buster uses .11 and Bullseye uses .15. Don't have the foggiest notion for whom Utopia was packaging. The work-around would be to use debs from Groovy Gorilla together with symbolic links name .13 pointing to the .14 files.

[mikeslr]

...
Having spent 30 years 'looking gift horses in the mouth', that's one red flag. Another is its involvement with cryto-currencies combined with the incentive to use them and the disclaimer that it won't hurt. I think you can accomplish most of Utopia's claimed benefits are by running tor under a vpn. Encrypt files before transmitting and you're using an encrypted transmission to send a differently encrypted file from an undisclosed location. And there are other ways to mask one's location...

Edit: Prominently displayed on protonvpn's opening page, https://protonvpn.com/ is the statement:
"
Tor over VPN
ProtonVPN also integrates with the Tor anonymity network. With a single click, you can route all your traffic through the Tor network and access Onion sites."
For some actual facts regarding this speculation see this thread, viewtopic.php?f=54&t=1457 among others.