Created attachment 184264 [details] Screenshot with Qt 6.10.0 beta 2 SUMMARY With Qt 6.10.0 beta 2 installed, all help pages are blank (screenshot attached). After downgrading to 6.9.1, all is OK So this seems like a regression in Qt. I'm reporting it here so that someone with sufficient knowledge (i.e. not me) can confirm that and identify the existing Qt bug, or raise a useful new one.
How did you get those qt and khelpcenter packages? Was khelpcenter rebuilt with new Qt? (not sure if it's needed but may be worth checking)
I'm seeing a related problem. On my Gentoo Linux system (Qt 6.9.1, Frameworks 6.16.0, Plasma 6.3.6, most apps 25.04.3) the local "Help" files were not being accessed via the "help" menu. Instead, I was referred to the internet (Firefox). After digging into this, I found that khelpcenter was no longer installed on my sytem. It used to be there, but now it's gone. When I reinstalled khelpcenter, the local docbook files started coming up from the help menus again. Maybe something similar is happening with other distros. I'll dig into my installation logs and see if I can figure out when khelpcenter was dropped.
(In reply to Albert Astals Cid from comment #1) Qt 6.10.0 is from the Arch "kde-unstable" repository and khelpcenter is built against Qt 6.9.1 Help Centre: 6.0.25080 KDE Frameworks: 6.17.0 Qt: Using 6.10.0 and built against 6.9.1 Arch Linux (Wayland) Build ABI: x86_64-little_endian-lp64 Kernel: linux 6.16.1-arch1-1 (In reply to David C. Bryant from comment #2) No, I don't think it's that, when I revert to Qt 6.9.1 it loads the local docbook files OK
Do you get any special warning when run from the command line?
(In reply to Albert Astals Cid from comment #4) ❯ khelpcenter rr600 device_uuid output is based on invalid pci bus info. View::langLookup "kdoctools6-common/kde-default.css" View::langLookup "khelpcenter/glossary/index.docbook" Backend texture is not a Vulkan texture. Compositor returned null texture The last two lines get repeated many times when I resize the window
I also noticed just now that if I drag the mouse across the white area where the help page should be, the "Copy" button activates. If I then press Copy, and then do edit - paste in Kate, I get the text of the help document. So it's as if the help page is there but being rendered white - on - white
Is webengine working at all in other applications?
(In reply to Antonio Rojas from comment #7) I'm not 100% sure which apps use qtwebengine, but trying some at random: 1. The preview pane in Klevernotes seems to misbehave similarly 2. The viewer pane in Akregator also has the problem ... so I guess the answer is no, webengine isn't working
It renders the help pages OK if I do: > QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu" khelpcenter (I got that idea from https://bugreports.qt.io/browse/QTBUG-138131, but that's raised against Qt 6.9.1 so not the same bug)
I'm using an AMD GPU: Operating System: Arch Linux KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.10.0 Kernel Version: 6.16.2-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 2 × AMD A6-6400K APU with Radeon(tm) HD Graphics Memory: 8 GiB of RAM (7.7 GiB usable) Graphics Processor: AMD CEDAR
If you create a file named main.qml with this contents import QtWebEngine WebEngineView { url: "https://kde.org" } and then on the console you run qml6 main.qml does it show something? If not webengine is broken and there's nothing we can do, you should update to beta3 and if it still fails report a bug upstream Qt. Also maybe instead of trying the arch packages try the ones from the Qt installer in case it's a Arch miscompilation.
(In reply to Albert Astals Cid from comment #11) Thanks for your help. That script shows only a blank white window, so I'll raise a Qt bug if it's still present with beta 3 Closing this bug now, I'll update it with the Qt bug reference when I've raised it.
... well, beta 3 arrived and plasma wouldn't launch at all. Going back to 6.9.1 for now.
(In reply to Paul Worrall from comment #13) > ... well, beta 3 arrived and plasma wouldn't launch at all. Going back to > 6.9.1 for now. This is caused by an ABI break in beta 3, should be fixed now in kde-unstable. As for the webengine issue, it is triggered by the mesa 25.2 update - downgrading to 25.1 fixes it.
(In reply to Antonio Rojas from comment #14) Thank you Antonio, I'm now on Qt 6.10.0 beta 3 with mesa 25.1.7 and all seems good :-)
Reported to https://bugreports.qt.io/browse/QTBUG-139424
*** Bug 509035 has been marked as a duplicate of this bug. ***
*** Bug 509357 has been marked as a duplicate of this bug. ***
*** Bug 509365 has been marked as a duplicate of this bug. ***