There's another alternative - debug in CI itself. There's a few ways that you can pause your CI at a specific step and get a shell to do some debugging, usually via SSH. I've found that to be the most useful.
It’s slow and arduous work to inject at the right point and find out what went wrong. But it’s miles better than act. act is a noble idea, and I hope it can meet its target, but it falls short currently.
ssh-action gets you on the host, and lets you quickly establish what is happening and implement fixes. It’s top notch!