Diagnosing "going live from an event view does nothing for ~5 s, with the status bar green" needed a
distinction the engine's own fields cannot make. `n` counts every stored sample, so it climbs whenever data
arrives at all; what says *why* nothing moves is the store's stamp pair beside it. So the line gains
`ring=[oldest..newest] n=`:
trig engine: … history=0.0000/0.4000 s … now_t=2.520 holdoff_until=2.520 ring=[2.5200..2.5200] n=567000
trig engine: … ring=[2.5200..2.5200] n=1131000
trig engine: … ring=[2.5200..2.5200] n=1689000
Three seconds apart, after `<live>`: the sample count climbs at the stream's rate (the data *is* arriving and
being stored) while the retained span is a single value — the file view's last stamp. So the producer's clock
is **frozen** after the restart, not lagging, which is why `history` never fills, why an armed trigger never
latches, and why a live view with the trigger off does not advance either: one cause, two faces, and it is
not the trigger.
The reading is what tells that apart from a stalled *feed* (ring moving, `now_t` still), which is a different
bug with a different fix — and neither is visible from `now_t` alone. `n` climbing beside a still `ring` is
the clock; a moving `ring` beside a still `now_t` is the feed.
The fix itself is the next piece of work: the producer's clock has to advance across a client restart (or the
file view's retained history has to go when going live), and this pair is the assertion it must satisfy —
after `<live>`, `ring` must move within a stream round-trip. Verified: `make test-ui` 14 files; the fields
observed in the transition run above; no `Gtk-CRITICAL`.
Martino Ferrari
62b5f14504