GitHub Actions steps.<id>.outputs Empty - Missing or Wrong Step id
A later step reads steps.<id>.outputs.<name> and gets an empty string because the producing step has no id, the id is misspelled, or the reference points at a step that has not run yet.
What this error means
An expression that should carry a value from an earlier step evaluates to empty. The workflow compiles fine, but downstream logic behaves as if the output was never set.
- run: echo "tag=v1.2.3" >> "$GITHUB_OUTPUT" # no id on this step
- run: echo "${{ steps.meta.outputs.tag }}" # prints emptyDiagnose it: print the context before you change anything
Most workflow-expression bugs are not syntax errors, they are an expression reading something that is empty. GitHub resolves a missing property to an empty string instead of failing the run, so a wrong reference looks like a logic bug rather than a mistake. Dump the contexts first and you will usually see the answer immediately.
- name: Dump contexts
run: |
echo '--- github ---' ; echo '${{ toJSON(github) }}'
echo '--- needs ---' ; echo '${{ toJSON(needs) }}'
echo '--- steps ---' ; echo '${{ toJSON(steps) }}'
echo '--- matrix ---' ; echo '${{ toJSON(matrix) }}'
echo '--- inputs ---' ; echo '${{ toJSON(inputs) }}'Check the context is allowed where you used it
Contexts are not available everywhere. The same expression can be valid in a step if and invalid in a job if, which is why an expression that works in one workflow fails when moved.
| Where you wrote it | Contexts available there |
|---|---|
run-name | github, inputs, vars |
concurrency | github, inputs, vars |
Top-level env | github, secrets, inputs, vars |
jobs.<id>.if | github, needs, vars, inputs |
jobs.<id>.steps.if | github, needs, strategy, matrix, job, runner, env, vars, steps, inputs |
jobs.<id>.outputs | Full access, including secrets |
Reusable workflow outputs | github, jobs, vars, inputs |
Common causes
Producing step has no id
steps.<id> only resolves for a step that declared an id. A step that writes to GITHUB_OUTPUT without an id cannot be referenced by any later step.
Typo or wrong id referenced
The id in the expression does not match the producing step exactly, or it refers to a step in a different job that the steps context cannot reach.
How to fix it
Give the producing step an id and reuse it
- id: meta
run: echo "tag=v1.2.3" >> "$GITHUB_OUTPUT"
- run: echo "Tag is ${{ steps.meta.outputs.tag }}"Confirm scope and ordering
- The reference must come after the producing step within the same job.
- For cross-job values, use job outputs and the needs context instead of steps.
- Match the id and output name exactly, including case.
Catch it before it reaches CI
Every failure in this cluster is statically detectable. actionlint parses workflow expressions, checks context availability against the same rules above, and validates needs references, so these bugs never need to cost you a run.
# one-off
docker run --rm -v "$(pwd):/repo" --workdir /repo rhysd/actionlint:latest -color
# as a job, before anything expensive runs
- uses: actions/checkout@v4
- run: |
bash <(curl -s https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
./actionlint -colorHow to prevent it
- Always add an id to any step whose outputs you consume.
- Use needs.<job>.outputs for cross-job data, steps.<id> only within a job.
- Echo the value once while wiring it up to confirm it is populated.