This is really only for debugging the logic of your Actions, isn't it? On my team, Nix seems to work pretty well for encapsulating most of the interesting thin

This is really only for debugging the logic of your Actions, isn't it? On my team, Nix seems to work pretty well for encapsulating most of the interesting things CI jobs do. We don't use virtualization to run local versions of our jobs, and we don't run into architecture mismatch issues.