The missing-binary fallback was a spawnSync, copied from the LTC listener
where the source is a third the size and builds in a few seconds. On the
production Mac this file took nearly two minutes, and spawnSync held the
Node event loop for every second of it: one module's optional helper froze
the entire dashboard, every other module with it, and then did it again
thirty seconds later on retry.
The build is now a plain spawn that reports "building" and calls start()
itself when it lands, so nothing waits on it. A failed build says so once
instead of spinning, and a build that never finishes is given up on after
five minutes.
The real lesson is the one in the comment: the binary should already be
there. It is built beside the app, or copied from any Mac of the same
architecture. Building on the machine that might be running a service is
the fallback, not the plan.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
