The code and its Enter were sent to `claude setup-token` in one write.
Claude Code's prompt reads a multi-byte chunk as a paste and swallows a
`\r` inside it, so the code filled the prompt but was never submitted and
the flow sat at "Waiting for setup-token to finish" until the 15-minute
timeout.
Measured against 2.1.283 under a pty: joined write never submits; the
same code with Enter 20 ms later submits every time. Now the code is
written, then Enter follows 250 ms later as its own write.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
shadowdaoandClaude Opus 5.5