What is the latest best practice to prefetch the hash?

[jtojnar]

@toraritte

Looked at the Update a package NixOS wiki article that reminded me of nix-prefetch-url ,

$ nix-prefetch-url https://github.com/aardappel/treesheets/archive

updated sha256 with the result,
[…]

but no joy

Right, fetchFromGitHub hashes the extracted source directory, while nix-prefetch-url hashes the downloaded file by default. As you discovered you will need to use --unpack when you want to use the hash for fetchzip or fetchFromGitHub, which often uses fetchzip internally.

@toraritte

updated sha256 with the result,

You can also just set the sha256 attribute to an empty string and Nix will tell you the correct one.

@toraritte

Just when I finished typing all this did I remember about nix-prefetch-url --unpack ,

$ nix-prefetch-url --unpack https://github.com/aardappel/treesheets/archive/4778c343ac78a3b3ccdaf079187b53d8cd64e235.zip
path is '/nix/store/bdwd3mcdfimd47ib15pqznf8hg4pwv8w4778c343ac78a3b3ccdaf079187b53d8cd64e235.zip'
1skh5hf86jn8q6lpdhwdyq62ny7x39j6mpsf63hvzys17z6nsaak

which works also, but then the format is totally different.

This is base-32 encoded hash, which sha256 attribute supports just as well.

---

In this case, there is an update script so you can just run the following in your Nixpkgs checkout:

nix-shell maintainers/scripts/update.nix --argstr commit true --argstr path treesheets

nixpkgs-update bot also does that periodically, someone just needs to notice the PR and merge it: treesheets: unstable-2022-03-12 -> unstable-2022-09-26 by r-ryantm · Pull Request #190656 · NixOS/nixpkgs · GitHub.