Hi,
I also developing on Leap 15, but rubocop and unit tests are only parts that does not depend on system. For development and  testing you depends on your system tools, libraries and configuration and I worry it will start more and more diverging. I think already some parts of code ( mainly not maintained by us ) uses TW tools, that are no available in SLE15. And I think it will get worse more and more. So I worry that having as goal to be able to develop for TW and ALP on Leap15 can be quite challenging.

Hi,

This may be a valid use case for distrobox[1]. It sets up a container for you with the linux distribution of your choice (e.g., Tumbleweed) and it can even include systemd if you want to (which makes sense for Agama).

Of course, if you need to fake some hardware, a VM is much better. But for some development work, it is worth a try. I have been playing around with it recently, and it does a pretty good job.

Regards,
Imo

[1] https://github.com/89luca89/distrobox