A workaround is to set XLIB_SKIP_ARGB_VISUALS=1 in the environment
before starting Emacs, or run Emacs as root.
+** Emacs built with xwidgets aborts when displaying WebKit xwidgets
+
+This happens, for example, when 'M-x xwidget-webkit-browse-url'
+prompts for a URL and you type the URL at the prompt.
+
+The error message might look like this:
+
+ X protocol error: GLXBadWindow on protocol request 151
+ Serial no: 4286
+ Failing resource ID (if any): 0x3c001c5
+ Minor code: 32
+
+This happens because starting from version 2.42.1, the WebKitGTK
+developers discontinued support for off-screen windows, by presuming
+that every window holding a WebView widget is an X server window
+eligible for an OpenGL context. Emacs requires placing these widgets
+within offscreen windows managed by GTK, for each xwidget might be
+displayed in multiple distinct windows, and its contents must be
+captured and reproduced within all of them if that be the case.
+
+To put this another way, WebKitGTK doesn't support displaying a single
+widget more than once anymore.
+
+A possible workaround is to make sure xwidgets are not shown in more
+than one window.
+
** Emacs crashes with SIGTRAP when trying to start a WebKit xwidget.
This could happen if the version of WebKitGTK installed on your system