The L3 commit added the test-extra-backend-parakeet-cpp-transcription
Makefile target but never invoked it in CI. Mirror the whisper job:
- Add a parakeet-cpp output to detect-changes (emitted by
changed-backends.js from the matrix entry).
- Add tests-parakeet-cpp-grpc-transcription, gated on the parakeet-cpp
path filter / run-all, building the backend image and running the
transcription e2e against tdt_ctc-110m + the JFK clip.
Assisted-by: Claude:claude-opus-4-8 [Claude Code]