actions-rust/README.md

actions-rust

Reusable Gitea Actions for Rust projects.

actions/rust-cache

Composite action that installs Rust, installs a prebuilt Mozilla sccache binary, and configures RUSTC_WRAPPER=sccache for later Cargo steps.

This action intentionally does not use Gitea actions/cache and does not cache target/. Rust build artifacts are cached through sccache; callers can use local sccache storage or an S3-compatible backend.

S3 usage

Create one shared bucket for Rust compiler artifacts, then pass non-secret S3 settings as inputs and credentials as normal workflow secrets.

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Setup Rust + sccache
        uses: https://git.ericxliu.me/eric/actions-rust/.gitea/actions/rust-cache@main
        with:
          toolchain: stable
          sccache-bucket: sccache
          sccache-region: auto
          sccache-endpoint: https://s3.example.com
          sccache-key-prefix: my-org/my-repo/linux-x64/stable
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.SCCACHE_AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.SCCACHE_AWS_SECRET_ACCESS_KEY }}

      - run: cargo test
      - run: sccache --show-stats

Local usage

Omit sccache-bucket to use the runner-local sccache cache:

- name: Setup Rust + local sccache
  uses: https://git.ericxliu.me/eric/actions-rust/.gitea/actions/rust-cache@main
  with:
    toolchain: stable

Inputs

• toolchain: Rust toolchain to install. Defaults to stable.
• sccache: Set to "false" to install Rust without configuring sccache.
• sccache-version: Mozilla sccache release tag. Defaults to v0.15.0.
• sccache-bucket: S3 bucket name. Empty means local sccache storage.
• sccache-region: S3 region. For S3-compatible endpoints, auto is usually right.
• sccache-endpoint: Optional S3-compatible endpoint URL.
• sccache-s3-use-ssl: Whether the endpoint uses TLS. Defaults to "true".
• sccache-s3-enable-virtual-host-style: Set to "true" only for endpoints that require virtual-host-style addressing.
• sccache-key-prefix: Optional cache key prefix. Defaults to repository, runner, and toolchain scope.
• sccache-wrap-cc: Wrap CC and CXX with sccache so build-script C/C++ compiles (e.g. libduckdb-sys, ring) hit the cache too. Defaults to "true". Set to "false" to opt out.

Notes

• Do not pass secret values as action inputs. Pass standard AWS environment variables from workflow secrets.
• CARGO_INCREMENTAL=0 is set because Rust incremental artifacts are not a good fit for sccache-backed CI builds.
• When sccache-wrap-cc is enabled, CC is exported as sccache cc and CXX as sccache c++. The cc crate splits on whitespace, so build scripts that go through it pick up the wrapper transparently. Build systems that do not support multi-word CC/CXX should opt out.
• SCCACHE_IGNORE_SERVER_IO_ERROR=1 is set so a cache outage falls back to local compilation instead of failing the build.
• SCCACHE_IDLE_TIMEOUT=3600 keeps the server alive across long build/test steps, which matters when the setup step has S3 credentials scoped only to that step.
• Add sccache --show-stats after build/test steps to inspect cache hit rates.