Tuist module cache for Buildkite

Keep Tuist's local cache across jobs on Tuist macOS runners. Every tuist command the step runs reads and writes its cache on storage that Tuist restores into the next job: module cache binaries, along with compiled manifests, plugins and selective testing results. Binaries the job finds locally do not have to be downloaded again.

steps:
  - label: Test
    agents:
      queue: tuist-macos
    plugins:
      - tuist/module-cache#v1: ~
    command: |
      tuist generate --no-open
      tuist test

The pre-command hook sets TUIST_XDG_CACHE_HOME to the restored cache and TUIST_CACHE_MAX_BYTES to its share of the storage, so the Tuist CLI evicts the least recently used binaries before the cache fills up. Authenticate and configure the module cache as usual; the plugin only decides where its local copy lives.

Successful builds Tuist can verify as coming from your own repository save their changes. Builds from forks start empty and never save. The module cache shares its storage and size budget with the Xcode cache plugin. Directories you keep with the tuist/cache-volume plugin are separate.

On agents that are not Tuist macOS runners the hook does nothing. If the runner could not restore the cache, the hook warns and the build runs with an empty one; it never fails the step.

This plugin's distribution repository is tuist/module-cache-buildkite-plugin. SOURCE_COMMIT records its monorepo source.