Can nixos test run in userland virtualization?

This would allow you for example to run integration tests on github actions, asside from it being much faster (since you don’t need to boot a vm!)

Running tests on GH actions is possible, but awfully slow. See which requires 3m 44s.

What exactly do you mean by “userland virtualization”?

virtualization without having to boot a vm,
eg docker, bsd jails, “bubblewrap” or something similar.

It is inefficient to boot a vm and causes issues like kvm not being supported by github actions.
I think on hercules I ran into another issue such as a limit on how many virtual machines could run at the same time on qemu, this sorta bottle-necks the ci pipeline, because only 1 or 2 jobs could run at the same time.

Ah yes, then no.

In their current state NixOS tests rely quite heavily on VMs (AFAIK).