GitHub Actions

How to run rsconstruct in a GitHub Actions workflow.

Recommended flags

- name: Build
  run: rsconstruct build -q -j0

Flag	Why
`-q` (quiet)	Suppresses the progress bar and status messages. The progress bar uses terminal escape codes that produce garbage in CI logs. Only errors are shown.
`-j0`	Auto-detect CPU cores. GitHub-hosted runners have 4 cores (`ubuntu-latest`) — using them all speeds up the build significantly vs the default of `-j1`.

Full workflow example

name: Build
on: [push, pull_request]

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

      - name: Install rsconstruct
        run: cargo install rsconstruct

      - name: Install tools
        run: rsconstruct tools install --yes

      - name: Build
        run: rsconstruct build -q -j0

Runner sizing

Runner	Cores	RAM	Notes
`ubuntu-latest`	4	16 GB	Good for most projects. Use `-j0` or `-j4`.
`ubuntu-latest` (private repo)	4	16 GB	Same hardware as public repos.
Large runners	8-64	32-256 GB	For large projects. `-j0` scales automatically.

-j0 always does the right thing — it detects the available cores at runtime. There is no benefit to setting -j higher than the core count.

Caching

Cache the .rsconstruct/ directory between runs to skip unchanged products:

      - uses: actions/cache@v4
        with:
          path: .rsconstruct
          key: rsconstruct-${{ hashFiles('rsconstruct.toml') }}-${{ github.sha }}
          restore-keys: |
            rsconstruct-${{ hashFiles('rsconstruct.toml') }}-
            rsconstruct-

This restores cached build products from previous runs. Only products whose inputs changed will be rebuilt.

Tips

Don’t use --timings in CI unless you need the data. It adds overhead.
Use --json instead of -q if you want machine-readable output for downstream processing.
Use -k (keep-going) to see all failures at once instead of stopping at the first one.
Use --verify-tool-versions to catch tool version drift between local and CI environments.