Bug 256873 – [GTK] gsk_gl_command_queue_create_render_target: assertion failed (glCheckFramebufferStatus (GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) when opening webkit://gpu

• Component: WebKitGTK
• Status: RESOLVED FIXED

I've seen this MiniBrowser crash on opening webkit://gpu with gtk4, but was informed it works with epiphany and gtk4 on fedora.
I'm attaching the output of bt full, Maybe others  have seen this or can suggest what might be different in my setup?

this was on webkit version 2.41.3 gtk-4.10.3

[Michael Catanzaro]

(In reply to enometh from comment #0)
> I'm attaching the output of bt full,

You forgot to attach the backtrace.

Created attachment 466383 [details]
gdb backtrace from Minibrowser webkit://gpu on GTK4

(sorry, apparently my connection dropped the first time I uploaded the file, but bugzilla detected that definitely asked me to attach it again when i logged in again, and I did. I assumed it worked, but it didn't)

[Michael Catanzaro]

This bug is https://gitlab.gnome.org/GNOME/gtk/-/issues/5392 which is supposed to be already fixed in the version of GTK that you are using. O_O I'll ping Benjamin.

[Michael Catanzaro]

Here is our feedback:

> yeah, not surprised as long as webkit randomly uses GL without GTK involvement
> 
> might be a case of the user using GLX and webkit deciding on EGL or vice versa
> 
> the only fix is to not do that, make them clear_current() each other's current contexts or implement webkit's GL context on top of GdkGLContext

This looks like

[Michael Catanzaro]

I was going to say "This looks like we're doing something wrong with OpenGL" but decided not to, since that's obvious. Then I forgot to delete the first half of my sentence.

More from Benjamin:

> well, the problem here is webkit taking over GL in the UI process and confusing GTK

hmm a similar crash occurs on 2.41.1 even with gtk3.  I passed -DENABLE_GLES2=on explicitly to cmake, which results in a cmakeconfig.h with
```
#define ENABLE_GLES2 1
#define USE_OPENGL 0
#define USE_OPENGL_ES 1
#define USE_OPENGL_OR_ES 1
```
What combination of options avoids such a crash?

I tried the same webkit with epiphany master from a few days ago.
Both with GDK_BACKEND x11 and wayland.

The crash  occurs when I start it from the command line arg webkit://gpu
However if I load another webpage first and enter webkit://gpu through
the location input bar, it does not crash and I get a valid page with
all the fingerprinting info

It may be possible to see what epiphany is doing right with the GL stuff
that fixes it?

[Carlos Garcia Campos]

Pull request: https://github.com/WebKit/WebKit/pull/14063

[Carlos Garcia Campos]

I can't reproduce the crash, could you try the patch in the PR, please?

I got around to compiling 2.41.4. I don't see the webkit://gpu crashes on gtk3
I saw before.
With gtk4 On X11 if I do GDK_DEBUG=gl-egl MiniBrowser webkit://gpu
there is no crash.
Otherwise there is a crash.
After applying this patch from commit 2b7bd3f23 (I think I've doing it correctly)
the situation is the same.

[EWS]

Committed 264311@main (edc3fa95e515): <https://commits.webkit.org/264311@main>

Reviewed commits have been landed. Closing PR #14063 and removing active labels.