Ultimately, you need someone to verify releases and that probably means paying for it. I know Sonatype paid solutions utilise their own internal research to allow/block new releases.
There needs to be a service that does reproducible builds of opensource projects as they sit and publishes results for people to scrape freely.
To be robust itself against attacks, likely 3-4 services.
But then that needs funding to be sustainable … and companies are incredibly cheap. Especially right now. As such… shrug :(
Maybe something as a skill for LLMs to run that actually checks build reproduction from source for a project and all of its dependencies? But then that’s gonna burn some tokens ….
I do this for personal projects … but at work they’ve started rationing tokens… as such… idk?