Migrating Windows CI to Qt 6.7 - Roadblocks

[christoph at cullmann.io]

On 2024-05-26 11:42, christoph at cullmann.io wrote:
> On 2024-05-26 10:49, Thomas Friedrichsmeier wrote:
>> On Sat, 25 May 2024 13:02:41 +0200
>> christoph at cullmann.io wrote:
>>> Now that frameworks is QDBus free on Windows and macOS I would even
>>> propose that in a next update of the stuff we really not have QtDBus
>>> around at all on these systems and make the use optional for the apps
>>> that want to support them.
>>> 
>>> We go to great lengths to avoid that dbus stuff is ever called, even
>>> deleting the dll and the most freezes you will get if that is not
>>> done is just dbus related.
>>> 
>>> It would be great if people could join the effort to get that right.
>>> 
>>> https://invent.kde.org/packaging/craft-blueprints-kde/-/issues/17
>> 
>> Asking mostly out of curiosity, but do you have a link to a writeup /
>> thread on the problem, and / or suggested replacements? I noticed
>> before that you were skeptical of dbus on Windows over at kate, but
>> since it essentially seemed to work for us in RKWard (for the very
>> limited use-case of reusing a running instance), I never bothered to
>> follow suit.
>> 
>> Now I see how you replaced dbus for that use-case in kate, and I guess
>> that'll be easy enough to copy. But if dbus is something to avoid
>> (where possible) in the interest of present and future cross-platform
>> compatibility, some generic guidance might be helpful.
> 
> I think the guidance is easy:
> 
> Beside on desktop Linux or BSD, there
> is just no DBus session or system bus running.
> 
> Therefore there is nothing to talk to and if you don't ensure yourself
> one is properly started (like KDE Connect seems to do) it will just not
> work (and more important: makes no sense).
> 
> For the re-use of instances you need to use something like
> 
> https://github.com/KDAB/KDSingleApplication
> 
> or similar.

It would actually be nice to have something like that as framework part.

In Kate we use Qt SingleApplication as we need a blocking message and 
more and more copies of similar stuff creep in.

> 
> Any implicit starting of the dbus stuff will often just result in hangs
> or other misbehavior.
> 
> It is just like X11: don't use it on systems that don't have it as
> native windowing system, we guard that the same way.
> 
> Greetings
> Christoph
> 
>> 
>> Regards
>> Thomas