Post

We improved our package builder Rattler-Build a lot over the past months, so we wrote a blog post about it! prefix.dev/blog/whats-...

Our parser is now stricter. This means great error messages for undefined variables and ambiguous match specs. Unfortunately that also means that some recipes that used to work, have to be adapted to work with the newest Rattler-Build version.

We also extracted library crates so you can create your own application based on Rattler-Build code. With this crate, for example, you can parse YAML files with the same jinja functionality built-into recipe V1 files: crates.io/crates/ratt...

For interactive development, Python is still king, which is why made sure to publish a convenient and powerful Python wrapper. We even expose functionality not found on the CLI, like the package assembler that lets you assemble packages directly without a recipe.

For a long time, we wished for an online playground so we can quickly check how a recipe renders and what packages produces. Thanks to web assembly, we are now able to provide exactly that: playground.rattler.build/

Iterating on recipes can be painful if you always have to iterate from scratch. This is why introduced `rattler-build debug` that lets you directly jump into your fail build without re-building environments or artifacts.

One of the most requested features is to have a common cache for package builds similar to what conda-build provides. Our goal was to have a solid design for that and after many iterations we are now confident with our approach.

We also worked on making the conda ecosystem supply-chain security aware. This is why we added experimental support for validating attestations of sources.