New package request

[1nonlyshadow]

Add libxml2 and libxslt development packages🙌

[jay-aye-see-kay]

Dev packages are often separate outputs on the standard package

devbox add libxml2 --outputs out,dev
devbox add libxslt --outputs out,dev

You can see available outputs on nixhub, e.g. https://www.nixhub.io/packages/libxml2

(The packages you're asking for are already packaged and usable)

[drewgingerich]

I'll add that I believe opening an issue at NixOS/nixpkgs is a better place to request new packages. Devbox uses Nix under the hood, and nixpkgs is the central open-source Nix package repository.