I'm new to QT and QML, I found a cool KDE Plasma addon on the internet and wanted to edit it, but flushMode property, which I want to use, was introduced in QT 5.13. I have installed QT 5.15 (to be exact, 5.15.3), rebooted and got file:///filename.qml:58:2: "VideoOutput.flushMode" is not available in QtMultimedia 5.8. I also checked that qt5-multimedia is 5.15.3+kde+r0-1 (latest from arch linux repository), checked the QT version in system settings, everything says it's 5.15, but in the logs it acts like it's 5.8. Is it possible that I have 2 different qt5 installations, or why does this happen?
Yes, you very likely have two Qt installed. You got system Qt package that comes with desktop environment, I believe it does not include development files (headers), to obtain them you installed qt-something-dev package that installed another Qt as dependency.
Related
As per my information, Binaries (or offline/online installers) for installing Qt (>= 5.6) on 32-bit linux are not provided. For example, If I want to use Qt 5.9.0 on 32-bit linux (debian, specifically), the only option is to download Qt source and build it. I have successfully built Qt 5.9.0 on my 32-bit linux machine. But I have to do this on all my development PC's. Instead if I can build it once and create an installer somehow, that will save a lot of time. Is there a way to create offline installer (e.g. *.run files) for installing Qt 5.9.0 on 32-bit Linux (e.g. debian)?
As stated by #Velkan, Qt is available on 32 bit Debian from the official repos.
But, indeed, there is no 32-bit Linux installer from the Qt project.
Regarding copying a Qt install from a Debian PC to another, you do not need to create an installer. Just copy/tar/zip the directory in which Qt is installed. The only requirement is that you must keep the installation in the same absolute path as the Qt Core library has the path hardcoded in it and it is use for plugin detection.
NB1: It is possible to patch Qt Core library to change the hardcoded path and even make it relative. It is not officially documented but you can take a look in the sources of tools like windeployqt or the online installer
NB2: Do not use Qt 5.9.0, prefer 5.9.2. Both are forward and backward binary compatible, but the latter received bug fixes.
I am installing OMNET++ 5.1.1. However, during the installation, it is reported that:
configure: error: Cannot build Qt apps, probably due to missing or too old Qt packages. Make sure Qt development packages are installed and newer than Qt 5.4. You can disable Qtenv by setting the WITH_QTENV variable to "no" in configure.user.
Then I download and install the Qt from https://www.qt.io/download/. But it still report the same problem. How can I solve this problem ? Thank you.
I assume you're running some kind of GNU/Linux, because on Windows and macOS, the bundled Qt libraries should just work.
Try installing the Qt5 development packages using your distro's native package manager, then they should be detected.
If you can't, or they are too old, take a look in the configure.user file, and adjust the value of the QT_PATH variable according to the instructions there.
EDIT:
Since the OS was clarified: On Windows, you don't need to download Qt, or any other library separately. They are all bundled with the OMNeT++ distribution, and should work fine.
Just make sure you always use the included mingwenv shell to install and run OMNeT++. In it, the environment variables are set up as necessary.
If you are installing OMNET++ on windows make sure you extract the zip file to a folder other than "Program Files" and deactivate your antivirus during the installation process.
I downloaded the QT 5.2 build for MingW/OpenGL build and installed it. When I run QTCreator and try to create a project, I can't set it up because there is no kit available to choose from. I have MingW installed, so I tried to point QT to this installation, but there is qmake as well missing. I'm not sure if the manual configuration of the compiler would suffice to have a kit to choose from, but that would be my expectation.
So the question is, how do I setup QT properly that it recognizes my MingW installation and how do I get qmake to continue with QT? After downloading a 600MB package I would have expected that it works out of the box.
OS is Windows 7 and my MingW uses gcc 4.8 so it should be the same version that QT brings in it's package as well.
I just installed Qt 5.2 package on ubuntu. I simply created a Qt widget application, and when I tried to build it, I got the following message:
Qt Creator needs a compiler set up to build. Configure a compiler in
kit options
I have tried several things, all of which were unsuccessful. I tried setting the compiler kit to
Desktop Qt 5.2.0 GCC 32bit (default)
However it didn't work
After that I set the compiler to
GCC (x86 32bit in use/bin)
However that didn't work either.
I also tried adding gcc manually and gave it the path
/usr/bin/g++-4.6
but it still didn't work.
This is what appears in there Qt Version tab
This is what I get when I remove the .pro.user file and restart the IDE, Whats the difference between configuring a project as Desktop and Desktop Qt 5.2.0 GCC 32bit?
Qt Creator needs a version of tools that are able to link against the Qt binaries that the downloaded package contains. In your case, the local toolchain and the binaries don't match. That means that you would actually have to build the Qt with your toolkit and make sure that QtCreator can find the built binaries.
The simpler way for Ubuntu is to use the packaged version of the tools; they play well with the already delivered binaries. Use sudo apt-get install qtcreator to install it with all the dependencies.
I’ve downloaded QT 5.2 mingw. Then i had trouble with QtCreator loading the plugings(compiled with mingw). After that i found that the QtCreator is built with MSVC 2010!!!!
So why in Qt 5.2 (which is built with Mingw), its QtCreator is built with MSVC?!
Probably because all Qt Creator releases are built once and repackaged in the various installers. It's not a good reason, and might even be a bad reason given your problem, but it's probably the reason. Note the Qt SDK is not meant to be used for actual Qt (Creator) development (you will use the git repositories for that), which is probably why nobody ever ran into this mismatch.
Note you can easily rebuild Qt Creator from source. It's as simple as
qmake ../qt-creator-3.0.0 -r
mingw32-make release
If you have a qt-creator-3.0.0-build directory next to the extracted source.