Output getting started guide to GH actions on push

.github/workflows/ci.yml

@@ -58,3 +58,30 @@ jobs:
  - name: Run integration tests
  # Runs only tests annotated with the `ignore` attribute (which in this repo, are the integration tests).
  run: cargo test --locked -- --ignored
+
+ pack-getting-started-output:
+ runs-on: ubuntu-22.04
+ steps:
+ - name: Checkout
+ uses: actions/checkout@v3
+ - name: Install musl-tools
+ run: sudo apt-get install musl-tools --no-install-recommends
+ - name: Update Rust toolchain
+ run: rustup update
+ - name: Install Rust linux-musl target
+ run: rustup target add x86_64-unknown-linux-musl
+ - name: Rust Cache
+ uses: Swatinem/rust-cache@v2.5.1
+ - name: Install Pack CLI
+ uses: buildpacks/github-actions/setup-pack@v5.2.0
+ - name: Pull builder image
+ run: docker pull "heroku/builder:22"
+ - name: Clone ruby getting started guide
+ run: mkdir tmp; git clone https://github.com/heroku/ruby-getting-started tmp/ruby-getting-started
+ - name: Install libcnb-cargo for `cargo libcnb package` command
+ run: cargo install libcnb-cargo
+ - name: Compile ruby buildpack
+ run: cargo libcnb package
+ - name: Getting started guide output
+ run: | # Use `script -e -c` to pretend to be a TTY for pack terminal color suport
+ script -e -c "pack build my-image --builder heroku/builder:22 --buildpack heroku/nodejs-engine --buildpack target/buildpack/debug/heroku_ruby --path tmp/ruby-getting-started"

README.md

@@ -233,7 +233,7 @@ Make sure it doesn't say `/usr/bin/ruby` or another system ruby location
 As a oneliner:
 
 ```
-$(set -pipefail; cd buildpacks/ruby && cargo libcnb package; cd ../..) &&
+cargo libcnb package &&
 docker rmi my-image --force &&
 pack build my-image --buildpack target/buildpack/debug/heroku_ruby --path buildpacks/ruby/tests/fixtures/default_ruby --verbose &&
 docker run -it --rm --entrypoint='/cnb/lifecycle/launcher' my-image 'which bundle'