An interactive shell orphaned by its hosting console dying (killed
conhost/terminal) previously spun ~2 cores forever: the Tcl 9 windows
console driver never delivers the dead-console state to the script as a
fileevent (tclWinConsole.c ConsoleEventProc only notifies on buffered
data) while its reader thread busy-loops on the persistent channel error,
so the script level is completely blind and nothing ever closes the
channel.
Fix: repl::console_watchdog - a self-rescheduling liveness poll (default
5s, repl::console_watchdog_ms; read-only GetConsoleMode probe via
chan configure -inputmode) armed by repl::start only for a tcl9 console
input channel serving the process-default console on windows. On probe
failure it closes the input channel (stopping the driver's reader
thread) and finishes the repl via the normal eof done-path; app-punkshell
then finds no console reopenable and exits cleanly. Piped, foreign-console
and tcl 8.6 inputs never arm it. repl::start's post-vwait reader
deregistration now tolerates a watchdog-closed channel.
Verification (2026-07-12): kill procedure post-fix exits the orphan in
1.5-2.0s with no traceback (src mode and rebuilt kits punkbi/punk91/
punk902z); 25s live-console soak shows no spurious trigger, CPU delta 0;
piped stdin unaffected; repl consolebackends 3/3 and punk::console suites
88 pass / 1 skip; root cause verified against plain tclsh 9.0.3.
Upstream ticket filed: https://core.tcl-lang.org/tcl/tktview/f10d91c2d3
Included:
- goals: G-039 flipped achieved 2026-07-12 and archived (index entry to
GOALS-archive.md, detail file to goals/archive/ with full root-cause,
repro and verification record); reference sweep adds the eof done-value
producer note to G-038
- src/modules/punk/AGENTS.md: watchdog contract documented
- project version 0.12.1 -> 0.12.2 + CHANGELOG entry
- vfs payload sync: _vfscommon.vfs punk/repl 0.4.0 -> 0.5.0
Assisted-by: harness=claude; primary-model=claude-fable-5; api-location=anthropic.com
Julian Noble