Under The Hood - Pantsbuild Open Source Community Blog

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Under The Hood

A collection of 7 posts

A woman in a white lab coat and safety googles dropping a liquid from a dropper into a test tube

How we get quick feedback on new features via "experimental" backends

Pants balances release velocity and end-user stability via judicious use of deprecation cycles. Experimental backends are a way to get quick feedback on new functionality, before "graduating" it to the formal deprecation policy. Experimental features are still well-supported, and not to be feared!

A visualization of a directed acyclic graph with about seventy vertices

Concepts Featured

Dependency inference: Pants's special sauce

Unlike earlier build systems, Pants v2 automatically infers your code's internal and external dependencies. And it does this at the file level, so that you get optimal invalidation, caching, and concurrency performance without having to manually create and maintain mountains of BUILD file metadata.

Skipping GitHub Actions jobs while keeping branch protection rules that require them

Skipping GitHub Actions jobs while keeping branch protection rules that require them

How we worked around some quirks and limitations of GitHub Actions to skip CI jobs that aren't necessary in certain scenarios, without breaking branch protection rules that normally require those CI jobs to succeed.

How we streamlined Apple M1 Support with self-hosted Github Actions runners

How we streamlined Apple M1 Support with self-hosted Github Actions runners

We ended up setting up a self-hosted GitHub Actions runner, on a hosted Mac M1. Getting the machine itself up and running was easy, thanks to MacStadium's simple, effective UX. But setting up the GHA runner on it was a little trickier, for a couple of reasons...

Talk Notes: PyCon US 2022 – Hermetic Environments in Pantsbuild

Talk Notes: PyCon US 2022 – Hermetic Environments in Pantsbuild

On Sunday 1 May 2022, Pants Maintainer, Christopher Neugebauer gave a talk about Pantsbuild's hermetic environments. Here are some useful resources: * Example Python repo [https://github.com/pantsbuild/example-python] — the codebase where you can run the demos from the start of the talk. * Stu Hood – Faster incremental builds with Speculation

Fast Incremental Builds with Speculation and Cancellation

Fast Incremental Builds with Speculation and Cancellation

Fast incremental re-builds are critical in large codebases and monorepos. Thanks to deep support for cancellation and a side-effect free execution model, Pants is able to further reduce re-build latency by speculatively re-executing work.

Dependency inference: Precise caching and concurrency, without the boilerplate

Dependency inference: Precise caching and concurrency, without the boilerplate

Scalable build tools have historically meant a significant boilerplate burden. But it doesn’t have to be that way! Pants v2 supports all of the caching, concurrency, and introspection you need to scale your repository, with significantly less boilerplate, thanks to… Dependency inference!