qtwebengine qmake error: unkown module: webchannel - qt

I am trying to get qt webengine running on my laptop for the first time, but can't seem to build it. I am following the instructions from here:
https://wiki.qt.io/QtWebEngineHowToTry
On the last few steps, I had to run "qmake -r" on the qtwebengine directory. This is the output:
SSL............................... Using system NSS
ICU............................... Using internal copy (Default, force system ICU with WEBENGINE_CONFIG += use_system_icu)
FFMPEG............................ Using internal copy (Default, force system FFMPEG with WEBENGINE_CONFIG += use_system_ffmpeg)
Proprietary codecs (H264, MP3).... Not enabled (Default, enable with WEBENGINE_CONFIG += use_proprietary_codecs)
Reading /home/kevin/workspace/qtwebengine/src/src.pro
Reading /home/kevin/workspace/qtwebengine/src/core/core.pro
Reading /home/kevin/workspace/qtwebengine/src/core/core_gyp_generator.pro
Project ERROR: Unknown module(s) in QT: webchannel
This error happened right after I installed WebKitGtk+ from here (http://trac.webkit.org/wiki/BuildingGtk) and ran "Tools/gtk/install-dependencies" and "Tools/Scripts/update-webkitgtk-libs". Before I installed WebKitGtk+, qmake would terminate at a later point.
(I installed WebKitGtk+ because, previously, running "qmake -r" on the qtwebengine directly resulted in an "unmet dependency: harfbuzz" error that I tried to fix on my own via google, and the WebKitGtk+ page was the only lead I could find that would supposedly fix that issue... big mistake!).
I am running on a (mostly freshly reformatted) Ubuntu 15.04 laptop. I installed qt5 via apt-get install, but apparently I have both qt4 and qt5 plugins installed, as well as qtchooser (I'm guessing from the WebKitGtk+ installation scripts).
Here is the output of "qmake --version":
QMake version 3.0
Using Qt version 5.4.1 in /usr/lib/x86_64-linux-gnu
Any help would be greatly appreciated, as I'm excited to try out qt webengine!

In case anyone else has the same problem, I fixed it by installing qt 5.5.0 from here http://download.qt.io/official_releases/qt/, and using the associated qmake binary from that installation. I guess installing qt from 'sudo apt-get install' still has some issues that won't work with qtwebengine.

Related

Qt - where to get /opt/qt59/bin/qt59-env.sh?

I have a project which relies on /opt/qt59/bin/qt59-env.sh which sets up QT environment. Without it, qmake complains:
Project ERROR: Unknown module(s) in QT: quick quickwidgets
It's not on my system (Ubuntu 17.10). I have QT 5.9 installed through qt5-default. I have been looking around but can't find. I've tried packages qtscript5-dev but qt59-env.sh did not appear.
What should I install to get it? Or what's an alternative to set up the environment?
Ubuntu's default packages don't include this kind of script.
qt59-env.sh comes from qt59base, that is from this ppa.
The ppa is for Ubuntu xenial (16.04), but it could also work on 17.10.
Otherwise you can just download qt59-env.sh from here and modify the paths to your installed Qt version.

Unable to locate package libqt5webkit5-dev

Suddenly today, without us changing any configuration, all test containers began to fail because of the following error:
$ sudo -E apt-get -yq --no-install-suggests --no-install-recommends --force-yes install libqt5webkit5-dev qtdeclarative5-dev
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package libqt5webkit5-dev
E: Unable to locate package qtdeclarative5-dev
We have the following configuration in our .travis.yml in order to use QT5 on Travis with Ubuntu 12.04:
apt:
sources:
- ubuntu-sdk-team
packages:
- libqt5webkit5-dev
- qtdeclarative5-dev
We've tried to fix this but are baffled. Any ideas? Anyone else experiencing this?
We had the same problem and after contacting Travis support I learned that apparently the ubuntu-sdk-team has stopped providing packages for Precise and you need to switch dist to Trusty. In order to get the builds working again add this to your .travis.yml file
sudo: required
dist: trusty
You can read more about it here
Ubuntu 12.04 will be deprecated in less than a year from now (exactly at 2017-04-26), and also Qt Webkit is deprecated with the new versions of Qt starting from Qt 5.5. It is removed in Qt 5.6 from the Qt distribution:
With 5.6, Qt WebKit and Qt Quick 1 will no longer be supported and are
dropped from the release. The source code for these modules will still
be available. You can continue to compile and use these modules, but
we will not be supporting them any longer.
http://blog.qt.io/blog/2016/03/16/qt-5-6-released/
So, you in order to maintain the stability of your development environment, either you have to stay with the current versions of Ubuntu and Qt (which has its own issues), or you have to port your code to work with the newer versions of Ubuntu and Qt, like Qt 5.5 on Ubuntu 16.04 LTS.

PyQT5 error: could not find or load Qt platform plugin xcb

Up until Anaconda3 (which contains Python 3.4) was re-installed on my RedHat 6.5 workstation, I have been able to develop Python apps that use PyQT5.
Post re-install of Anaconda I receive an error message:
....could not find or load Qt platform plugin xcb
The only difference between Anaconda installs is the folder name: /usr/local/ananaconda3 vs /usr/local/anaconda_py3
I checked libqxcb.so has no missing dependencies.
I rebuilt PyQT5.
I tried explicitly adding location of site-packages of PyQT5:
import site
site.addsitedir("...path.../python3.4")
Any other suggestions?
How does re-installing Python impact the use of PyQT5?
This is an error caused by having two different versions of Qt under the same installation/environment.
Check the packages installed and their versions in your environment (if for some reason you're not working in a virtual environment, you can skip the first line):
source activate yourenvname
conda list
If you see pyqt and qt both with version 4.X.X then remove them (assuming you want to work in Qt v5):
conda remove qt
conda remove pyqt
I had an issue that seems to match what happened here.
But in my case the solution was to "sudo rm -rf user/anaconda3" and reinstall it with "bash anaconda....sh", because I had previously installed it using sudo ("sudo bash anaconda....sh")

Project ERROR: Unknown module(s) in QT: websockets

I'm trying to run a simple client example using QTWebsockets using Qt Creator, already add the
QT += websockets
But it throws this when i run build or qmake
:-1: error: Unknown module(s) in QT: websockets
I tried
QT += core websockets
Then realized that since installed Qt Creator from the repositories it wasn't up to date, so I reinstalled it from the Qt website but the problem persisted, I then ran pkg-config --modversion QtCore and it returns 4.8.6, thing is, in the QT version tab of qt creator it shows 5.4.1 to GCC compiler which is the compiler I’m using, in /opt/Qt/5.4/gcc_64/lib there is the QT5WebSockets module even in the help tab are listed the QT5 modules but I can't use them.
Tried with SerialPort and it didn't work, tried with Opengl and it worked which means is a version problem but I can't seem to find how to solve.
sudo apt-get install libqt5websockets5-dev
I solved it, the problem was that I just opened the project I made with qt4, when I tried to build it in the freshly installed qt creator the .pro.user file kept pointing to all qt4.
Solution, create a new project and add the source from the first, or change all the references from qt4 to qt5.
sudo zypper install libqt5-qtwebsockets-devel

Ubuntu 13.04 -> opencv and qt installation

I'm trying to install opencv (2.4.5) with Qt in my fresh Ubuntu 13.04.
I've downloaded opencv, executed:
ccmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ../opencv-2.4.5
../opencv-2.4.5 is the folder of the opencv source
and in ccmake I changed the WITH_QT variable to YES
than make and sudo make install
But now if in kdevelop I try to execute my test code (I only call addText(...) over an image). I get the following error:
OpenCV Error: The function/feature is not implemented (The library is compiled without QT support) in fontQt, file...
What I'm doing wrong?
Thanks in advance for any suggestion
edit: I had both qt4 and qt5 due to the QtCreator installation.
For a fast solution I removed qt5 and qtcreator and reinstalled opencv.
Now it works, but is there a cmakelist for opecv that enable to use qt5?
Have you looked at This Using CMake with Qt 5
I'm not sure if I should answer my question, anyway:
If you look at the github repository of OpenCV, 4 days ago the CMakeList.txt has been updated to support Qt5.
So the solution is to clone the project and install it from source.
I tested it and it works.

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