cmd opens '>>' redirection targets write-exclusive, so when the STARTED
and terminal hook children appended to one shared log concurrently, the
loser of the open race hit a sharing violation and silently dropped its
marker line -- a permanent loss that surfaced as an intermittent
Windows-CI-only failure of the macro-bracketing suite (the engine's exit
drain was verified sound: spawn intent is registered synchronously at
fire time and covers macro-context fires). One file per event makes
writer overlap impossible while keeping every exact-count assertion
byte-identical.
Hook processes are fire-and-forget: the binary's exit drain acknowledges
spawns only, so the STARTED writer can land after the terminal one. The
macro-bracketing tests waited only for the terminal marker and then
asserted STARTED's count immediately, flaking on Windows CI and loaded
Linux runners. The bounded wait now covers every expected marker before
the exact-count and absence assertions run; the probe script's scenario K
comment is corrected to state the spawn-ack-only contract it already
waits around.
The fixture's hook commands were sh-only: single-quoted redirect targets
are literal under cmd /C, so the marker log never received content and
all six tests timed out on windows-latest. Build the marker command
per-platform — parenthesized `(echo MARKER)>> "log"` on Windows to
avoid cmd's trailing-space echo gotcha — and move the interpolated
paths into single-quoted YAML scalars so Windows backslashes are not
read as double-quoted-scalar escapes. Also replace the cleanup call
that a wait timeout skipped with a drop guard, so failed runs no
longer leak temp dirs.
The --macro dispatch arm now opens the top-level agent bracket before
macro_execute and closes it signal-aware afterwards, draining pending
hooks like the --execute arm; both bracket calls no-op without a loaded
agent, so agent-less macro runs are unaffected. The isolated arm of
macro_execute closes the bracket an in-macro .agent step opens on its
fresh context, on the step-failure path too. Binary-level tests pin
agent.started plus exactly one terminal event for the --agent flag and
for in-macro .agent steps in both isolation modes, on success and
failure.
Dark-Alex-17