Unknown module(s) in QT: webenginewidgets

Christian Ehrlicher

You can select single components in the Qt online installer.

JacobNovitsky

How should I proceed? I have another machine with Qt installed with online installer

SGaist

Hi,

Since you already installed Qt using the online installer, go to the folder and use the Maintenance Tool to modify your installation.

JacobNovitsky

it does not work
Cannot initialize cache: Cannot obtain the lock for file "/home/j/.cache/qt-unified-linux-online/cache.lock": Resource temporarily unavailable

ChrisW67

As @Christian-Ehrlicher pointed out: if you built your Qt instance from source, then you need to reconfigure it to include the Web Engine components, rebuild, and reinstall.
If, as @SGaist has assumed, you installed your entire Qt from the online installer, then you need to run the Maintenance Tool, select the missing component(s), and let it install them for you.

The error message you posted seems to indicate that you are trying to install Qt using the online installer on top of an existing self-built Qt. You cannot add a component to an existing self-built Qt using the Qt Online installer. To install a completely new Qt instance you need to install into a fresh directory.

jsulm

@JacobNovitsky said in Unknown module(s) in QT: webenginewidgets:

Cannot obtain the lock for file "/home/j/.cache/qt-unified-linux-online/cache.lock": Resource temporarily unavailable

Is Qt Online Installer still running? If so close it and try again.
If it does not help delete that file manually.

JacobNovitsky

I've removed all components with Maintenance tool, then reinstalled
Qt and Web engine with online installer

Trying to compile sample project:

QT += widgets webenginewidgets
CONFIG += c++17
SOURCES += main.cpp

#include <QApplication>
#include <QWebEngineView>
#include <QUrl>

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);

    QWebEngineView view;
    view.resize(1200, 800);
    view.load(QUrl(QStringLiteral("https://www.qt.io")));
    view.show();

    return app.exec();
}

getting error:
:-1: error: Unknown module(s) in QT: webchannel positioning

Kindly advise!
q.png

jsulm

@JacobNovitsky said in Unknown module(s) in QT: webenginewidgets:

webchannel positioning

Same: did you install these two modules?

JacobNovitsky

libqt6webchannel6/jammy,now 6.2.4-1ubuntu1 amd64 [installed,automatic]
libqt6webchannel6-dev/jammy,now 6.2.4-1ubuntu1 amd64 [installed,automatic]
1wlibqt6positioning6/jammy,now 6.2.4-1 amd64 [installed,automatic]
libqt6positioning6-plugins/jammy,now 6.2.4-1 amd64 [installed,automatic]
libqt6positioningquick6/jammy,now 6.2.4-1 amd64 [installed,automatic]
qt6-positioning-dev/jammy,now 6.2.4-1 amd64 [installed,automatic]

SGaist

@JacobNovitsky If you are using the Qt version from the online installer, you have to add these dependencies from the online installer as well...

Or just use the Qt version from your distribution. However you cannot mix and match.

JacobNovitsky

Should I install above libraries with version 6.9.2? (as per my Qt version)

jsulm

@JacobNovitsky You should install these libraries for the Qt version you're using.
You wrote:
"I've removed all components with Maintenance tool, then reinstalled
Qt and Web engine with online installer"
Doesn't that mean that you now need to install these modules using Qt Maintenance Tool from that Qt installation?

AsifBahrainwala

This post is deleted!

JacobNovitsky

All modules installed, version of module is the same as Qt -> 6.9.2
getting error when trying to build below:

:-1: error: Project ERROR: Unknown module(s) in QT: webchannel positioning

TEMPLATE = app
TARGET = webengine_test
QT += core gui widgets webenginewidgets   # <-- webenginewidgets is required

CONFIG += c++17

SOURCES += main.cpp

#include <QApplication>
#include <QWebEngineView>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QWebEngineView view;
    view.resize(800, 600);
    view.load(QUrl("https://www.qt.io")); // any test URL
    view.show();

    return app.exec();
}

hskoglund

SGaist

@JacobNovitsky when you say all modules installed:

from the same source ?
are you using the Qt version with all the modules installed to build your application ?

enjoysmath

Yo yo. I'm having this exact same issue. Both with 6.8 and 6.5.3. I'm guessing same thing willl happen with 6.10 if I were to try it out... Can't install and use webenginewidgets. I just need a single browser window for rendering KaTeX and taking snapshots of it... Anyone know of a quickfix?

Windows 10, 64bit.
I only use Widgets-side for desktop apps.

Same dealio with webchannel. All installed!

enjoysmath

@JacobNovitsky Were you able to fix this? Having same issue independent of you building yours from source, since mines just the standard community installer on Windows 10!

Bonnie

@enjoysmath Are you using Qt kit of MinGW? Webengine doesn't support MinGW, you must using MSVC kits.
(Refering to: https://doc.qt.io/qt-6/qtwebengine-platform-notes.html#windows)

Note: Currently, Qt WebEngine does not compile with MinGW.

Qt Webengine module won't be installed on MinGW kit even you have it checked in the installer.

You also need to install Qt Webchannel and Qt positioning in Additional Libraries.
(Refering to: https://doc.qt.io/qt-6/qtwebengine-index.html)

Note: By default, Qt WebEngine depends on the Qt Positioning and Qt WebChannel optional modules, but can be built without them. Be sure to install these add-ons when using the online installer.

With all these installed rightly (by online installer), I can use webenginewidgets with Qt 6.8.3 on Windows 10.

enjoysmath

@Bonnie

I use the installer gotten to via Qt Creator 18.0.0 > Tools > Qt Maintenance Tool > Start Maintenance Tool.

I have Qt WebEngineWidgets/Channels/Positioning installed now across the board. Do I need to include qt positining in the Qt += line of the .pro?

And yes, always trying MSVC first. So now I know now to even try out MinGW option...