check-gig: a dead surface driver blocks the launch

The LCXL LEDs probe exits 0 with no surface on the bus, so its only failure
is hardware present and its translator down: no faders reach Ardour, no paint.
That is 'there is no gig', not advice. It sat as one WARN among eleven under
two stale FAILs and went unread.

tools/check-gig.py

@@ -62,7 +62,7 @@ from pathlib import Path
 
 sys.path.insert(0, str(Path(__file__).resolve().parent))
 
-from gig_gate import ADVISE, MACHINE, WARN, Gate, Probe, shell  # noqa: E402
+from gig_gate import ADVISE, BLOCK, MACHINE, WARN, Gate, Probe, shell  # noqa: E402
 
 ROOT = Path(__file__).resolve().parent.parent
 PY = sys.executable  # whatever runs the gate runs its children: one interpreter
@@ -365,7 +365,14 @@ print(" ".join(str(p) for p in m.setlist_tracks()))')"""),
         fi"""),
           fix="start the painter: LCXL3 -> systemctl --user start lcxl3-driver; "
               "original LCXL -> systemctl --user start lcxl-leds-watch",
-          kind=ADVISE),
+          # BLOCK, not ADVISE, since 2026-10-11. The probe already exits 0 when no
+          # surface is on the bus (absent hardware is ADVISE territory), so the
+          # only way it fails is the surface PRESENT and its nervous system down:
+          # no faders reach Ardour, no paint, no OLED. That is "there is no gig".
+          # It was ADVISE, and that day it sat as one WARN among eleven while two
+          # stale FAILs (since fixed) carried the NO-GO, so the one real fault was
+          # the line nobody read.
+          kind=BLOCK),
 
     # Asks whether THIS instance warmed, by keying to the unit's own start time
     # — not "was there ever a PRELOAD line", which a previous boot would satisfy

tools/tests/test_check_gig.py

@@ -280,3 +280,15 @@ def test_the_launcher_does_not_grow_its_own_gate():
     body = "\n".join(ln for ln in src.splitlines() if not ln.lstrip().startswith("#"))
     assert 'run "' not in body, "the launcher is growing gate assertions"
     assert "check-gig.py" in body, "the launcher must END by calling the gate"
+
+
+def test_a_dead_surface_driver_blocks_the_launch():
+    """2026-10-11: LCXL3 on the bus, lcxl3-driver down, no fader reaching Ardour.
+
+    The probe exits 0 when no surface is plugged in (absent hardware is not a
+    reason to refuse a gig), so its only failure is hardware present and its
+    translator dead. That was ADVISE, one WARN among eleven, under two stale
+    FAILs. Demoting it again is how the real fault gets missed.
+    """
+    probe = next(p for p in CG.PROBES if p.name == "LCXL LEDs")
+    assert probe.kind == gig_gate.BLOCK