sccache-action

The sccache action can be used in GitHub Actions workflows to integrate sccache into the build process. The sccache action is a step in a workflow that can be used to cache compilation results for subsequent builds, reducing the build time and speeding up the overall development process.

sccache can easily use GitHub actions cache with almost no configuration.

This action is available on: https://github.com/marketplace/actions/sccache-action

Notice

This action is forked from mozilla/sccache-action. It adds a TOS (Volcengine Object Storage, S3-compatible) backend so that Rspack's self-hosted CI can cache compilation results in TOS, reusing the same credential convention as rstackjs/rust-cache.

The action is a drop-in replacement: when BUCKET_NAME is not set, its behaviour is identical to upstream.

Big thanks to mozilla/sccache-action creators and contributors for their great work. ❤️

Diff

Differences with mozilla/sccache-action:

• Added TOS (S3-compatible) backend
  • Translates the rust-cache TOS env convention (BUCKET_NAME / REGION / ENDPOINT / ACCESS_KEY / SECRET_KEY) into the SCCACHE_* / AWS_* variables that the sccache binary reads
  • Explicitly set SCCACHE_* / AWS_* variables still take precedence
  • No behaviour change when BUCKET_NAME is absent

Usage

Just copy and paste the following in your GitHub action:

Use the latest version of sccache if no version is specified

- name: Run sccache-cache
  uses: mozilla-actions/sccache-action@v0.0.10

Conditionally run cache and enable it

- name: Run sccache-cache only on non-release runs
  if: github.event_name != 'release' && github.event_name != 'workflow_dispatch'
  uses: mozilla-actions/sccache-action@v0.0.10
- name: Set Rust caching env vars only on non-release runs
  if: github.event_name != 'release' && github.event_name != 'workflow_dispatch'
  run: |
    echo "SCCACHE_GHA_ENABLED=true" >> $GITHUB_ENV
    echo "RUSTC_WRAPPER=sccache" >> $GITHUB_ENV

Specify a given version of sccache

Versions prior to sccache v0.10.0 probably will not work.

- name: Run sccache-cache
  uses: mozilla-actions/sccache-action@v0.0.10
  with:
    version: "v0.10.0"

To get the execution stats

Note that using the previous declaration will automatically create a Post Run sccache-cache task.

- name: Run sccache stat for check
  shell: bash
  run: ${SCCACHE_PATH} --show-stats

disable stats report

- name: Run sccache-cache
  uses: mozilla-actions/sccache-action
  with:
    disable_annotations: true

Rust code

For Rust code, the following environment variables should be set:

    env:
      SCCACHE_GHA_ENABLED: "true"
      RUSTC_WRAPPER: "sccache"

C/C++ code

For C/C++ code, the following environment variables should be set:

    env:
      SCCACHE_GHA_ENABLED: "true"

With cmake, add the following argument:

-DCMAKE_C_COMPILER_LAUNCHER=sccache
-DCMAKE_CXX_COMPILER_LAUNCHER=sccache

With configure, call it with:

# With gcc
./configure CC="sccache gcc" CXX="sccache gcc"
# With clang
./configure CC="sccache clang" CXX="sccache clang"

Use TOS (Volcengine Object Storage) as the backend

sccache stores its cache through its own S3-compatible backend, so this action only translates the TOS env convention (shared with rust-cache) into the SCCACHE_* / AWS_* variables that the sccache binary reads. Set the following env, and the action wires up the rest:

- name: Run sccache-cache
  uses: mozilla-actions/sccache-action@v0.0.10
  env:
    BUCKET_NAME: my-sccache-bucket
    REGION: cn-beijing
    ENDPOINT: tos-s3-cn-beijing.volces.com # S3-compatible domain, note the `tos-s3-` prefix
    ACCESS_KEY: ${{ secrets.TOS_ACCESS_KEY }}
    SECRET_KEY: ${{ secrets.TOS_SECRET_KEY }}
- name: Set Rust caching env vars
  run: echo "RUSTC_WRAPPER=sccache" >> $GITHUB_ENV

Notes:

• The S3-compatible API needs the tos-s3- host, not the native TOS SDK domain. A native ENDPOINT (e.g. tos-cn-beijing.volces.com, shared with rust-cache) is rewritten to its S3-compatible form (tos-s3-cn-beijing.volces.com) automatically. The native host rejects AWS SigV4 with Unsupported Authorization Type (EC 0002-00000002).
• When ENDPOINT is omitted, it is derived as tos-s3-${REGION}.<domain>, where <domain> is volces.com on macOS and bytepluses.com elsewhere. SSL is on by default; override it with SCCACHE_S3_USE_SSL if needed.
• SCCACHE_S3_ENABLE_VIRTUAL_HOST_STYLE defaults to true: TOS's S3-compatible API rejects path-style requests with InvalidPathAccess (EC 0003-00000002) and only accepts virtual-hosted style.
• Cache objects are namespaced under SCCACHE_S3_KEY_PREFIX, defaulting to ${GITHUB_REPOSITORY}.
• Any explicitly set SCCACHE_* / AWS_* variable takes precedence over the translation above.
• Do not set SCCACHE_GHA_ENABLED when using TOS.

Using on GitHub Enterprise Server (GHES)

When using the action on GitHub Enterprise Server installations a valid GitHub.com token must be provided.

- name: Run sccache-cache
  uses: mozilla-actions/sccache-action@v0.0.10
  with:
    token: ${{ secrets.MY_GITHUB_TOKEN }}

Note that using https://github.com/actions/create-github-app-token is a better option than storing a fixed token in the repo secrets.

Prepare a new release

1. Update the example in README.md
2. Update version in package.json
3. Run npm i --package-lock-only
4. Run npm run build
5. Commit and push the local changes
6. Tag a new release (vX.X.X)
7. Create a new release in github

License

Apache-2.0 (just like sccache)