Master => main change broke all clients
The clients work by retrieving emojis on demand from Github and storing them in a local cache. Clients are (still, today) hard coded to retrieve emojis from the "master" branch, which was moved to the "main" branch. As a result Github is serving 404's for all emoji URL's. This probably explains #385.
See e.g. https://github.com/buildkite/cli/blob/main/local/emoji.go#L22-L26.
@kevinburke thanks for the report.
Buildkite has been growing quite quickly and I don't think anyone on the team responsible for emojis (my team!) realised that the bk cli was using this repo in such a way.
As a really quick and dirty "fix" I've pushed a master branch to GitHub, based on the current main branch. Obviously that won't update though, so we'll have a chat internally about a long term fix.