### Check existing issues - [x] I've verified that this bug isn't described by any existing issues. ### Bug description When using `yes | snapcraft promote xxx --from-channel latest/edge --to-channel latest/beta` in a GitHub Actions workflow to promote a snap from edge, the step exits 0 and CI stays green, but the promotion does not happen. This behavior has started with snapcraft 9. ``` Warning: snapcraft promote does not have a stable CLI interface. Use with caution in scripts. Build set information for 'latest/edge' Arch Revision Version arm64 635 0.295.0 Channel promotion cancelled ``` Migrating to the new supported syntax, `--yes`, the promotion starts working correctly. Yet, it would be great to make the old syntax fail with error. ### Steps to reproduce A github workflow with the following step ``` - name: Promote `xxx` snap from edge to beta env: SNAPCRAFT_HAS_TTY: "true" run: | yes | snapcraft promote xxx --from-channel latest/edge --to-channel latest/beta ``` ### Environment Github CI, independently from the chosen runner. ### snapcraft.yaml ```yaml If the issue is specific to a project, share its `snapcraft.yaml`. This field automatically renders as YAML, so you don't need to add special formatting. ``` ### Log output ```shell Provide any relevant logging. This field automatically renders as a log, so you don't need to add special formatting. ```