The action runner currently fails to strip color codes from the output. This means that many matchers currectly do not work. https://github.com/actions/runner/issues/2341 https://github.com/actions/runner/pull/2430 The new matcher is copied from kaj/rsass which is MIT licensed. 3e5d6c0600/.github/workflows/rust-problem-matcher.json
3e5d6c0600/.github/workflows/rust-problem-matcher.json
The regex for the problem matcher is invalid, since the `-` creates a range. But the range is invalid, since it cannot start with `\s`.