Limit coveralls to reading lcov output

Fixes #4043

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index cb6c100d40e2a4d106eca708c4dc5382ceb13985..c6c54c71dd2bc94e62f660e439cdcec541598083 100644 (file)
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -64,6 +64,7 @@ jobs:
       with:
         github-token: ${{ secrets.github_token }}
         flag-name: ubuntu-${{ matrix.ubuntu }}-ruby-${{ matrix.ruby }}
+        format: lcov
         parallel: true
   finish:
     name: Finalise