sh.tangled.repo.setDefaultBranch now replies with the refs record's {uri, cid} (Tangled 65434cb4a). atgc repo default-branch drops the reply, and the doc comment at src/cmd/repo/branch.rs:93-94 still describes the old behaviour. The fix is to carry uri and cid into --json and correct the comment. With awaitRecord, atgc could then wait on that record.
Needs a decision: this adds output fields.