Random advice on how to debug WebEngine issues. Still WIP.
Deleting application settings
Qt WebEngine does cache things in your local user account, and sometimes this causes crashes or asserts on startup, especially when switching between different Qt (and therefore WebEngine) versions.
To clear the cache, manually delete your application settings folders.
Windows: Delete the directory named after your executable in %APPDATA%, %LOCALAPPDATA%
Linux: Delete the directory named after your executable in
Getting a Stacktrace
To get a better stack trace, launch your application with '--single-process' argument.
TODO: qtdiag, QT_OPENGL=software.
Getting Debug Output
Both Qt and Chromium provide valuable debugging output. For Linux, this is usually shown in the console. For Windows though, it will only appear if you launch your app in a debugger, or with a tool like dbgview.
To increase the debugging log in release mode, run with '--enable-logging --log-level=0'.