* fix(pty): release ptmx fd on natural exit + defuse SIGHUP-to-recycled-pid
Daemons accumulated ptmx fds over time because node-pty's UnixTerminal
only releases the master fd when destroy() runs. On the natural-exit
path (the common case — user closes a tab, shell runs `exit`) nothing
ever calls destroy(), so the fd leaks until GC. On macOS this
eventually hits kern.tty.ptmx_max=511 and all new terminals fail to
spawn.
Fix: release the fd synchronously on every teardown path (natural
exit, explicit kill, stale SSH spawn, daemon shutdown) and close the
concurrent SIGHUP-to-recycled-pid hazard inside node-pty's
UnixTerminal.destroy().
- src/main/daemon/pty-subprocess.ts: synchronous POSIX proc.kill
neutralization inside proc.onExit; dead guards on forceKill/signal
so they never target a reaped-and-possibly-recycled pid
- src/main/daemon/session.ts: new disposeSubprocess() for already-
exited sessions (fd release only, no SIGKILL) — avoids sending
SIGKILL to a recycled pid during daemon shutdown
- src/main/daemon/terminal-host.ts: dispose loop routes on isAlive —
live sessions get forceKillAndDisposeSubprocess (SIGKILL + fd
release), exited sessions get disposeSubprocess (fd release only)
- src/main/providers/local-pty-provider.ts: same POSIX kill
neutralization at top of onExit for the legacy local path
- src/relay/pty-handler.ts: same neutralization in wireAndStore;
disposed flag guards all public entry points; dispose() uses
SIGKILL (not SIGTERM) before destroy since the relay is exiting;
killTimer fallback + immediate-shutdown + stale-spawn cleanup all
call disposeManagedPty + ptys.delete so wedged children (D-state,
bad NFS) can't leak map entries against the 50-PTY cap
Windows is exempt everywhere — WindowsTerminal.destroy IS a kill()
call internally (closes the ConPTY agent), so neutralizing would
turn destroy into a no-op and leak the agent.
See docs/fix-pty-fd-leak.md for the full design.
Co-authored-by: Orca <help@stably.ai>
* fix(pty): patch node-pty native off-by-one leaking /dev/ptmx per spawn
node-pty 1.1.0's pty_posix_spawn on macOS walks low_fds[0..2] in an
allocation loop that breaks at the first fd >= STDERR_FILENO, then
cleans up via `for (; count > 0; count--) close(low_fds[count])`. In
the typical case (break at count=0) the cleanup body never runs and
low_fds[0] — a /dev/ptmx handle — leaks per spawn. Fixed upstream in
microsoft/node-pty af053f2 (PR #882), not in any 1.1.0 release.
Backport the 3-line cleanup-loop fix as a pnpm patch. E2E validated
against a dev daemon: 200 spawn/kill cycles kept the daemon's ptmx
fd count flat at baseline; prior runs reproduced linear 1-per-spawn
growth. Also documents the native root cause as a status addendum in
docs/fix-pty-fd-leak.md — the JS-side destroy() discipline previously
landed is still load-bearing for the SIGHUP-to-recycled-pid hazard and
for synchronous fd release on daemon shutdown.
Co-authored-by: Orca <help@stably.ai>
* fix(pty): capture stable kill spy ref in pty.test.ts
destroyPtyProcess reassigns proc.kill = () => {} on POSIX to defuse
the SIGHUP-to-recycled-pid hazard (see docs/fix-pty-fd-leak.md). After
that reassignment, proc.kill.mock is undefined and the assertions
crashed in CI. Capture a stable reference to the vi.fn() before it
gets reassigned.
Co-authored-by: Orca <help@stably.ai>
---------
Co-authored-by: Orca <help@stably.ai>
Jinwoo Hong
Neil