Under the hood
Failures installing the fast, non-blocking stdout writer now log more detail and report telemetry once per reason
What
Claude Code uses a fast, non-blocking way of writing to the terminal's standard output when possible. When that setup fails to install, the log message now includes the specific system error code (errno) instead of a generic message. A new 'skipped' telemetry event is also sent, but only once per distinct failure reason (duplicates are filtered out), alongside the existing 'installed' event that already reported successes.
Why
This makes it easier to diagnose why the faster output path isn't being used on a given system, without flooding telemetry with repeated identical failure reports.
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The writer flagged doubt
The finding does not say what effect, if any, this has on the reader beyond diagnostics; behavior when the fast path fails to install is…