litellm/.github/actions/cache-cargo-build/action.yml

name: "Cache the Rust build"
description: >-
  Cache the Cargo registry and target directory the root package's build needs,
  so only the first job on a given Cargo.lock compiles the bridge from scratch.

  litellm builds through maturin, which compiles litellm-rust/crates/python-bridge
  in the dev profile for editable installs. `uv sync` therefore pays a full build
  in every job that installs the workspace. Nothing caught it, because the uv cache
  holds wheels uv downloads rather than wheels it builds, and a path dependency
  whose source moves every commit could never hit that cache anyway. Cargo rebuilds
  only what changed when its target directory survives, so a warm job pays for the
  bridge crate alone.

  The key namespace is separate from test-rust.yml's check and release caches. They
  cache the same directory for different workloads, and a shared key would let
  whichever ran first deny the others a save.

inputs:
  profile:
    description: "Cargo profile the build uses (dev or release)"
    required: false
    default: "dev"

runs:
  using: composite
  steps:
    - name: Restore the Cargo registry and target directory
      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
      with:
        path: |
          ~/.cargo/registry
          ~/.cargo/git
          litellm-rust/target
        key: ${{ runner.os }}-maturin-${{ inputs.profile }}-${{ hashFiles('litellm-rust/Cargo.lock') }}
        restore-keys: |
          ${{ runner.os }}-maturin-${{ inputs.profile }}-