Question

You are authoring a composite action that runs a shell script to compute a build hash, and you need to expose that hash as an output of the action so calling workflows can reference it via steps.<id>.outputs.build-hash. In the run step you have the value in a shell variable $HASH. Which combination correctly wires this up in the action's metadata and script?

Accepted Answer

In action.yml declare `outputs.build-hash.value: ${{ steps.compute.outputs.hash }}`, and in the step (id: compute) run `echo "hash=$HASH" >> "$GITHUB_OUTPUT"`.

Answer

In action.yml declare `outputs.build-hash.value: $HASH`, and in the step run `echo "::set-output name=build-hash::$HASH"`.

Answer

In action.yml declare `outputs: build-hash`, and in the step run `echo "build-hash=$HASH" >> "$GITHUB_ENV"`.

Answer

No metadata is needed; simply run `echo "build-hash=$HASH" >> "$GITHUB_OUTPUT"` and the output is automatically exposed by the composite action.