GitHub Actions matrix job "reserved characters in name"
Job and matrix-derived names render into the run UI and APIs. Certain control or reserved characters in a computed name cause validation or display failures. Keep names to plain text and safe punctuation.
What this error means
A matrix job with a name built from interpolated values fails validation or renders incorrectly because the value contains reserved characters.
github-actions
Invalid workflow file: .github/workflows/ci.yml#L30
The job name contains invalid characters.Common causes
Interpolated value has control/reserved characters
A matrix dimension injected into name includes characters not allowed in job names.
Unsanitized external input in name
A name built from arbitrary data contains characters that break rendering.
How to fix it
Sanitize the job name
- Build the name from safe matrix values only.
- Replace or strip reserved characters before using them in name.
- Prefer a stable readable label over raw interpolated input.
.github/workflows/ci.yml
strategy:
matrix:
os: [ubuntu-latest, windows-latest]
name: build-${{ matrix.os }}How to prevent it
- Keep job names to letters, numbers, dashes, and spaces.
- Avoid interpolating arbitrary external data directly into job names.
Frequently asked questions
What causes "Invalid characters in job name"?
A matrix dimension injected into name includes characters not allowed in job names.
How do I fix Invalid characters in job name?
Sanitize the job name
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