Include meta in package derivations

[khaled]

I'm using the following to generate a basic BOM:

nix bundle .#my-package --bundler bundlers#toReport

The report will include node packages, but the they are missing license and maintainer information. For example:

express-4.18.1 (no license) maintained by nobody

It would be nice if derivations generated for each package included meta extracted from their package.jsons. Typically they will include license, author, and contributor information. According to the package.json docs, licenses should generally use SPDX identifiers, which should hopefully make them easily to translate to meta.license.

[yusdacra]

I do this in nix-cargo-integration for Cargo projects. I can upstream that logic here and polish it up and add it to nodejs, rust and etc. subsystems.

[khaled]

@yusdacra that sounds like a lovely idea :)

[yusdacra]

I made #294 which adds licenses info for nodejs and rust. However, the report still doesn't work, because it doesn't handle multiple licenses (see https://github.com/NixOS/bundlers/blob/master/report/default.nix#L162-L168). But this isn't a dream2nix issue so it should be reported to bundlers repo. this was my fault, I fixed it now.