[Development] What to do if tests hang on the CI and I can't reproduce that locally?

[Ilya Fedin]

On Wed, 15 May 2024 07:33:11 -0700
Thiago Macieira <thiago.macieira at intel.com> wrote:

> On Wednesday 15 May 2024 03:12:26 GMT-7 Ilya Fedin wrote:
> > > But I still can't explain why XInternAtom would block. You'd need
> > > to get a backtrace of the X.org process to see if it is blocked.
> > > What does it mean to intern an atom? Does it send something to
> > > the root window to register it?  
> > 
> > As far as I understand it just registers a string as an integer ID
> > referred to as atom. So it's apparently just some string-integer map
> > inside X server.  
> 
> Also note that other tests ran fine after these deadlocked. So if the
> X server had had a major bug, we should be seeing everything after
> this test failing.
> 
> It's possible the bug does exist, just causing the reply to get
> dropped for this connection. But as it's that simple an
> implementation as you say, it isn't likely.

I guess the actual code in Xorg might be more complicated than needed
given that it had a problem with having a maintainer...

> > Yeah. Given that the event loop is in GTK code, it means it either
> > successfully handled the event in Qt code or haven't got to it yet.
> > None of which really explain the hang (other than a possibility of
> > triggering some bug inside X server).  
> 
> You said that GDK is using a different libxcb and libX11 connection
> from Qt. That means the Qt XCB code could not handle event sent to
> GDK nor vice-versa.

Yeah, it makes the problem only more weird...