By now it is probably no longer news to many: GNOME Shell moved from GJS’ own custom imports system to standard JavaScript modules (ESM).
Extensions that target older GNOME versions will not work in GNOME 45. Likewise, extensions that are adapted to work with GNOME 45 will not work in older versions.
You can still support more than one GNOME version, but you will have to upload different versions to extensions.gnome.org for pre- and post-45 support.
Please file bugs with your favorite extensions or have a friendly conversation with your extension writers so that we can help minimize the impact of this change. Ideally, you could help with the port and provide a pull or merge request to help maintainers.
I am a daily Gnome user. There are many things which I actually dislike about Gnome, but I have solved them all through extensions. Fine, I'm not bothered because it can be customized.
But every time they introduce something like this, it takes me a while to get a functional desktop back. It takes time for those extensions' developers to respond to these things. They have to research the change, implement it, test it, go through extra work to stay backward compatible, etc. These people aren't being paid for this, so it takes some time.
I'm just frustrated about this. I know someday I will run updates and suddenly find all my extensions broken.
I really, really hope Cosmic turns out to be a good DE, because Gnome does a lot of cool stuff that I really like, but the actual experience of using it is miserable for me. It always feels like it's fighting against everything I want to do.
I'm glad Gnome exists, but we need an option that does some of the cool and unique things they do while also being less opinionated.
I literally just moved to Gnome 44 from a long time Gnome 3 setup. I only found one extension that makes Gnome 4x feel usable the way gnome 3 was and that's v-shell. If v-shell breaks then I'm never moving to gnome 45.
The ideas behind the GNOME Shell desktop metaphor have stayed consistent through the 3.x cycle, at least from ~3.10. The "problem" with GNOME 3.x is that it implements core ideas in the workflow that the user needs to grasp. Either you use it as they thought you should or you are better off with some other DE.
Sure, you may need some extension to feel more comfortable. I do use a couple, but if you need extensions to make it functional you really should consider switching to another DE/WM.
I really like a lot about Gnome. It's things like getting rid of the system tray that don't make sense to me. I understand it's not in the system's ideology, but you can't force that on every application developer who still has to support that feature for other desktops. If it's a common application feature, then it's just broken on Gnome. That's a hard thing to sell me.
One of the reasons I prefer KDE or MATE. Too many extensions needed to make it usable. I also don't like the fact that they're installed through their website instead of your local package manager.