> this type of attestation is hard to weigh as a trust signal, vs the cloud CI version

In the sense that I'm not a large corporation and nobody else is auditing my personal computer, yes, that's true. Note, though, that large corporations are also subject to nefarious actors misusing their infrastructure. What if a rogue employee hacks their internal system? Or Russia or China manages to get a backdoor into it?

In any case, all this doesn't make the method I described impossible. It just means that attestations produced by an individual workflow need to be clearly labeled to distinguish them from attestations produced using a tech forge's workflow, so people will understand what, specifically, is being attested to. Then people could weigh each trust signal as they choose.

> Hand PGP signing

To be clear, I wasn't talking specifically about this method of signing with a personal key. I agree there are lots of issues with PGP as an overall system. I was only talking about the general idea of having some way for individuals to independently generate an attestation without having to go through a tech forge's workflow.