3->4 project conversion from Project Manager fails without Vulkan support even with "--rendering-driver opengl3"

[Foxysen]

Godot version

4.0.2

System information

Windows 10, GPU with no Vulkan support

Issue description

My GPU doesn't support Vulkan. I run Godot 4 with "--rendering-driver opengl3" argument.

I have tried to open my Godot 3 project from Godot 4 Project Manager. It asked me whether I want my project to be converted. I pressed "full conversion". Very shortly it gave me a error that it can't run Vulkan app and that I should use "--rendering-driver opengl3", which I already run. After it closed Project Manager for me and I reopened it, I could find the project in the Project Manager list and then open it. There was no error. However the convertion was minimal, just enough to run it in Godot 4. I believe that it didn't run a full auto-convertion.
This always happens when I repeat these steps.

Next I have used command line and launched Godot 4 from it with "--convert-3to4" argument, doing it on second copy of the same Godot 3 project. (Had to increase limits for it to convert everything.) The process went smoothly and final project could be opened without error as well. However it had a more full conversion in comparison. This makes me believe that conversion process fails in Project Manager method by not respecting "--rendering-driver opengl3" argument in the process (I don't know how it actually looks as I can't run it).

P.S. I also run Godot 4 with "--single-window" argument, as it glitches out for me otherwise. I don't know if it has an impact on my experience, but worth mentioning.

Bonus:
I have a suspicion that this issue
#74159
is related to this one and is actually a result of a failed conversion.

Steps to reproduce

Get GPU with no Vulkan support and try to convert any Godot 3 project from Project Manager while running with "--rendering-driver opengl3".

Minimal reproduction project

Any Godot 3 project, it just has to error on attempt.

[Calinou]

This sounds like a duplicate of #74159. The project converter does not set the renderer of the converted project, so it defaults to Forward+ on desktop, Forward Mobile on mobile and Compatibility on web. Since an automatic OpenGL fallback isn't implemented yet, this causes the editor to fail to open the project on GPUs that don't support Vulkan.

[akien-mga]

It probably doesn't require a fallback, the problem isn't what renderer the project itself is using, but what renderer is used by the project manager when starting a new process with the --convert-3to4 argument.

Making it default to OpenGL3 like the project manager might solve the issue of the files conversion not happening properly.

[Foxysen]

I think that akien-mga has got the source of my problem right and solution makes sense to me.

I will make sure to confirm if it solves my issue when I see it implemented in a compiled release.