gates: the today-override announces itself; malformed no longer swallowed

Part 6 of the hub-blindness task, separable and done rather than dropped.

Both due_checks_gate.py and instructions_gate.py read FELHOM_GATE_TODAY so
their suites can control "today", and neither said so. A shell that still has
it exported -- exactly what a session doing gate-test work leaves behind --
made both gates evaluate against a fabricated date and pass in SILENCE. That
is this project's own named failure class: an instrument that can quietly
return the wrong answer is not a measurement. The seam is legitimate and
stays; the silence was the defect.

Both now print a loud line naming the variable, its value, and that the real
date is being ignored, before any verdict.

And instructions_gate.py no longer swallows a MALFORMED override: it used to
fall through to the real date without a word while due_checks_gate.py already
exited 2 on the same input -- one variable, two gates, disagreeing about what
a mistake means. Both exit 2 now.

Tests extended in both suites (42 and 73 assertions, green). Red-proof: the
announcement was deleted from due_checks_gate.py and its two assertions were
seen failing, then reverted.

Also adds REPORT-hub-blindness.md (topic-suffixed; the shared REPORT.md is
left alone per the parallel-session rule).

scripts/CHANGELOG.md

@@ -1,3 +1,21 @@
+## due_checks_gate.py v1.0.1 + instructions_gate.py — the today-override announces itself (2026-08-18)
+
+**Both gates read `FELHOM_GATE_TODAY` so their suites can control "today"; neither said so.** A shell
+that still has it exported — exactly what a session doing gate-test work leaves behind — made both
+gates evaluate against a fabricated date and pass, **silently**. That is this project's own named
+failure class: an instrument that can quietly return the wrong answer is not a measurement. The seam
+is legitimate and stays; the silence was the defect.
+
+- Both gates now print a loud line naming the variable, its value, and that the real date is being
+  ignored, before any verdict.
+- **`instructions_gate.py` no longer swallows a MALFORMED override.** It used to fall through to the
+  real date without a word, while `due_checks_gate.py` already exited 2 on the same input — two gates
+  reading one variable and disagreeing about what a mistake means. Both now exit 2.
+
+Tests extended in both suites (valid → announced; malformed → exit 2). One red-proof: the
+announcement was deleted from `due_checks_gate.py` and its two assertions were seen failing, then
+reverted.
+
 ## due_checks_gate.py v1.0.0 — a dated check becomes a thing that bites (2026-08-18, R-341)
 
 **New gate, registered as #10 in `repo_gates.py` (`--fast`).** R-341 booked two dated measurements —

scripts/due_checks_gate.py

@@ -87,10 +87,17 @@ def today_utc():
     override = os.environ.get("FELHOM_GATE_TODAY")
     if override:
         try:
-            return datetime.strptime(override.strip(), "%Y-%m-%d").date()
+            d = datetime.strptime(override.strip(), "%Y-%m-%d").date()
         except ValueError:
             print("DUE-CHECKS GATE INCONCLUSIVE: FELHOM_GATE_TODAY=%r is not YYYY-MM-DD" % override)
             sys.exit(2)
+        # THE OVERRIDE ANNOUNCES ITSELF. A shell that still has this exported — exactly what a session
+        # doing gate-test work leaves behind — would otherwise make this gate evaluate a fabricated
+        # "today" and pass in silence. An instrument that can quietly return the wrong answer is not a
+        # measurement, so the seam stays and is made loud.
+        print("!! FELHOM_GATE_TODAY=%s IS SET — this gate is evaluating against that date, NOT "
+              "today's real UTC date. Unset it for a real run." % override.strip())
+        return d
     return datetime.now(timezone.utc).date()
 
 

scripts/instructions_gate.py

@@ -121,12 +121,29 @@ def effective(text):
 
 
 def today_tuple():
-    """Local date as (y, m, d). Injectable via FELHOM_GATE_TODAY for the test suite."""
+    """Local date as (y, m, d). Injectable via FELHOM_GATE_TODAY for the test suite.
+
+    THE OVERRIDE ANNOUNCES ITSELF (R-339 session, 2026-08-18). It is a legitimate test seam and the
+    suite depends on it — but a shell that still has it exported, which is exactly what a session
+    doing gate-test work leaves behind, silently made every date comparison here evaluate against a
+    fabricated day and pass. That is this project's own named failure class: an instrument that can
+    quietly return the wrong answer is not a measurement. So the override is kept and made LOUD.
+
+    A MALFORMED override is now exit 2, not a silent fall-through to the real date. Quietly ignoring
+    it means the run the operator thought they were doing is not the run that happened — and it also
+    made this gate disagree with due_checks_gate.py, which already exited 2. Same seam, same rule.
+    """
     override = os.environ.get("FELHOM_GATE_TODAY")
     if override:
         m = ISO_DATE_RE.match(override.strip())
         if m:
+            print("!! FELHOM_GATE_TODAY=%s IS SET — this gate is evaluating against that date, NOT "
+                  "today's real date. Unset it for a real run." % override.strip())
             return tuple(int(g) for g in m.groups())
+        print("FAIL: FELHOM_GATE_TODAY=%r is set but is not YYYY-MM-DD." % override)
+        print("      Refusing to fall back to the real date: the run you think you are doing would")
+        print("      not be the run that happens. Fix or unset the variable.")
+        sys.exit(2)
     import datetime
 
     d = datetime.date.today()

scripts/test_due_checks_gate.py

@@ -211,6 +211,27 @@ def test_g_gate_is_registered_in_the_runner():
           "due_checks_gate.py" in out)
 
 
+
+# ── Part 6 — the today-override must ANNOUNCE itself ─────────────────────────────────────────
+def test_override_announces_itself():
+    """A shell that still has FELHOM_GATE_TODAY exported must not be able to fake a run in silence."""
+    with tempfile.TemporaryDirectory() as tmp:
+        reg = make_register(tmp, HEADER + "| R-341 | 2099-01-01 | far future |\n")
+        rc, out = run_gate(reg, today="2026-08-20")
+        check("P6: valid override is announced", "FELHOM_GATE_TODAY=2026-08-20" in out and "IS SET" in out)
+        check("P6: the announcement says the real date is being ignored",
+              "NOT" in out and "real UTC date" in out)
+        check("P6: announcing does not change the verdict", rc == 0, "rc=%d" % rc)
+
+
+def test_malformed_override_is_inconclusive_not_a_silent_fallback():
+    with tempfile.TemporaryDirectory() as tmp:
+        reg = make_register(tmp, HEADER + "| R-341 | 2099-01-01 | far future |\n")
+        rc, out = run_gate(reg, today="not-a-date")
+        check("P6: malformed override exits 2", rc == 2, "rc=%d" % rc)
+        check("P6: names the variable and the bad value", "FELHOM_GATE_TODAY" in out and "not-a-date" in out)
+
+
 def main():
     print("test_due_checks_gate")
     for fn in sorted((v for k, v in globals().items() if k.startswith("test_")),

scripts/test_instructions_gate.py

@@ -516,6 +516,27 @@ def test_two_file_shape_still_checked_byte_identical():
         check("tally names the two-file shape", "two-file shape" in out)
 
 
+
+# ── Part 6 — the today-override must ANNOUNCE itself, and a malformed one must not be ignored ──
+def test_override_announces_itself():
+    with tempfile.TemporaryDirectory() as tmp:
+        root = make_repo(tmp, "# Repo\n")
+        rc, out = run_gate(root, today="2026-08-06")
+        check("P6: valid override is announced", "FELHOM_GATE_TODAY=2026-08-06" in out and "IS SET" in out)
+        check("P6: announcing does not change the verdict", rc == 0, "rc=%d" % rc)
+
+
+def test_malformed_override_exits_2_instead_of_silently_using_the_real_date():
+    """It used to fall through to today's real date without a word — and disagreed with
+    due_checks_gate.py, which already exited 2 on the same input. Same seam, same rule."""
+    with tempfile.TemporaryDirectory() as tmp:
+        root = make_repo(tmp, "# Repo\n")
+        rc, out = run_gate(root, today="not-a-date")
+        check("P6: malformed override exits 2", rc == 2, "rc=%d" % rc)
+        check("P6: names the variable and the bad value", "FELHOM_GATE_TODAY" in out and "not-a-date" in out)
+        check("P6: says it refuses to fall back", "Refusing to fall back" in out)
+
+
 def main():
     print("test_instructions_gate")
     for fn in sorted(