A stdio mcp_server orphaned by a dropped SSH session used to swallow
pipe errors in the generic exception handler and sleep forever on the
dead channel, holding the mine_palace flock (2026-07-10 write-path
outage, PID 23392). The loop now logs and shuts down on stdin EOF,
OSError from stdin reads (EIO/EBADF from orphaned ptys), and
BrokenPipeError/OSError on stdout writes. Shutdown returns from the
loop for a normal interpreter exit 0 — no os._exit — so held flocks
release via process teardown; a broken stdout is re-pointed at devnull
first so the shutdown flush cannot turn the exit into status 120.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DpEdb9SNWF42BpupHWBhC3
xcarbo