Not sure if the new cli has an equivalent command yet, but there is nix-store --verify --check-contents --repair which will check hashes of all store paths and redownload any that are corrupted.
You might want to do a gc before hand as this can take quite a while, depending on your machine.
That path is simply a checkout of Nixpkgs; the one used by your flake. Which nixpkgs revision was locked in your flake?
I’d try to nix-store --delete /nix/store/8ab0a9nkgm1d7cv22m923axawna0yj2z-source and eval again. It should download Nixpkgs again and hopefully that time it won’t be corrupted.
It should have never corrupted in the first place though. This is likely an issue in a lower layer. Check your ram and/or disk. There might be an issue brewing up that might turn out to be critical.
nix-store --verify --check-contents --repair found and fixed a lot of errors, but not all. And it couldn’t fix my issue. nix-store --delete /nix/store/8ab0a9nkgm1d7cv22m923axawna0yj2z-source removed the file, but then I just got error: cannot get archive member name: Damaged tar archive when I try to build my config again.
One RAM module is defective, I removed that now.
At least I can build my configuration again. I’m doing a nix-store --verify --check-contents --repair again.