What changed,
and why.

Release notes for Kiln, the build tool. Shipped every other Tuesday, written by whoever did the work.

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RSSUpgrade guide for 4.0npm i -D kiln@4.2.0
  1. v4.2.0Latest

    Warm remote cache on cold starts

    The first build on a fresh CI runner used to pay for everything. Now it pays for what changed.

    • New

      kiln cache warm primes the remote cache from the last green build before the first task runs.

    • Improved

      Cold builds on a 14k-module monorepo went from 3m 41s to 52s on an 8-core runner.

    • Fixed

      Watch mode no longer rebuilds twice when an editor saves by writing a temp file and renaming it.

  2. v4.1.2

    Source maps and profiles, fixed

    • Fixed

      Source maps for re-exported barrel files point at the original module again.

    • Fixed

      kiln build --profile writes valid JSON on Windows paths with spaces.

  3. v4.1.0

    Size budgets per package

    Set a ceiling per package. The build fails with a diff of what grew, not just a number.

    kiln.toml
    [budgets]"@acme/checkout" = "48 kB""@acme/search"   = "32 kB"
    • New

      Per-package size budgets in kiln.toml, checked on every production build.

    • New

      kiln why <module> prints the import chain that pulled a module into a chunk.

    • Improved

      Tree-shaking now drops unused class members in side-effect-free packages.

  4. v4.0.0

    Kiln 4

    A new resolver written in Rust, and Node 20 is the floor. Upgrade notes cover the three breaking changes.

    • New

      Rust module resolver: 6.1× faster on deep node_modules trees.

    • Improved

      Config errors name the key, the file and the line instead of a stack trace.

    • Fixed

      Circular imports through type-only re-exports no longer stall the graph walker.