qutebrowser: update to 3.0.0, use Qt6 by default

[ahesford]

We can make Qt6 a (default, when possible) build option to allow people to build Qt5 versions if desired, and also force the WebKit backend (which implies Qt5) when WebEngine is unavailable.

Testing the changes

• I tested the changes in this PR: briefly (I'm using it now)

cc: @daniel-eys

[loosefish-scapegrace]

I had some problems with the fixed bitmap font when i tried this (it had artifacts and rendered quite slowly), but i think that's a qt6 issue and not a qutebrowser issue. Apparently it was fixed in qt 6.5.2, which void has not packaged?

[ahesford]

I imagine the font rendering issue can be worked around by disabling bitmap fonts, as was the case with recent Firefox updates. Those with a compelling need for bitmap fonts (I'm curious to know what such a need might be) can either build the browser with the qt6 option disabled; alternatively, just manually install the Qt5 dependencies and pick that version with a command-line flag.

The fact that qt5-webengine is stuck at Chromium 8x and increasingly triggers warnings from websites looking to drop support (or functionality altogether) strongly motivates the move to Qt6 by default wherever possible.

[vlur]

Hi, since upgrading qutebrowser to v3.0, Invidious videos don't play in browser. Instead they throw the error "No compatible source found for this media". qutebrowser issue #7185 says this is due to the QtWebEngine binary not being built with proprietary codec support.

Dev of qutebrowser The_Compiler says:

Looks like Void Linux builds Qt 5 with proprietary codec support, but does not pass the same option for Qt 6. You might want to open an issue in their packaging repo for this, as it doesn't seem intentional.

I am not OP in that thread, but I am experiencing the same error. I can open an issue if that is preferred but I thought it might be better to just give you a heads up since this is probably a simple fix.

[loosefish-scapegrace]

There's an open issue (#44293) about enabling proprietary codec support in qt6-webengine

[vlur]

Ah, alright, my mistake. I tried to look for open issues first. Guess I missed it. Cheers.

[ahesford]

Until qt6-webengine is rebuilt with the necessary codecs, you can always manually install the PyQt5 dependencies and launch qutebrowser with qt5-webengine.