"No WebView plug-in found!" with Qt 6.2.3 on Linux

liteyear

I've build Qt 6.2.3 from source, passing -skip qtwebengine to ./configure to work around some showstoppers.

I have then been able to qmake and make a simple QML based project and run it on Linux with the -platform eglfs flag. When I was targeting Raspberry Pi OS, I'm sure the webview appeared. Now I'm targeting a Yocto based distribution, the dreaded "No WebView plug-in found!" error is back, and no webview appears.

I've tried every variation of QT += I can think of, lots of permutations of QtWebView::initialize(); and reviewed the Qt configure and make over and over looking for clues. I see /qt/plugins does not contain webview, however all the usual libqtwebviewquickplugin.so and libQt6WebView.so.6/libQt6WebViewQuick.so do appear in the right spots.

I've attached the output when I run my app with QT_DEBUG_PLUGINS=1 set. Argh, not enough permissions. Hang on... here it is as a gist.

What it required to get WebView to work on Linux in Qt 6.2, with WebEngine disabled?

SGaist

Hi,

You can't have it without on Linux as stated in the module documentation.

liteyear

Hmm, I see. The configure script disagrees:

Checking dependencies of 'qtwebview'
Skipping optional dependency 'qtwebengine' of 'qtwebview', because building 'qtwebengine' was explicitly disabled.

I thought for sure I had this working on RPiOS, and all the way from Qt configure to project build to app run, I'm led to believe I could. But that sounds pretty definitive, so perhaps it was just wishful thinking...

An excerpt from my notes:

There was some doubt about whether qtwebview had dependencies on qtwebengine, but I've proven by way of a running GUI on the Raspberry Pi 3B+ plus 7" Touchscreen, in X, VNC and bare console forms, that qtwebengine is not required.

It's been a long, long night, so maybe I got my wires crossed.

SGaist

Something may have changed and the doc is wrong. From what I remember, QtWebView makes use of the OS provided web API and on Linux (and Windows for that matter) there's not an OS based API that provides that.

I would be happy to be proven wrong though.

liteyear

Just to close the loop, I was unable to prove you wrong, @SGaist . I bit the bullet and recompiled with qtwebengine enabled (no small feat!) and everything started working the way I remembered it. So I think I may have led myself astray with optimistic recall.