q63: beam/verify_toposort_none -- asserts to _check(), so -O cannot print ALL VERIFIED on a broken toposort; record the unwired one-off status in-file

wizard-work/beam/verify_toposort_none.py

@@ -1,20 +1,30 @@
+# Q63 (2026-10-24): no committed gate invokes this file -- `git grep -F -n verify_toposort_none.py HEAD
+#   -- '*.py' '*.sh' CHECK` matches nothing outside this file -- so it is a one-off
+#   artifact, run by hand against its subject, not a standing check.
 """Verification artifact for toposort None-deps and one-shot materialisation."""
 import os, sys
 sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
 from toposort import topo_sort
 
+
+def _check(cond, msg="check failed"):
+    """Explicit failure path -- survives `python3 -O`, where `assert` is compiled away."""
+    if not cond:
+        raise SystemExit(f"FAIL: {msg}")
+
+
 def gen():
     yield "b"
 
 # None dep cases
 r = topo_sort({"a": None})
-assert r.sorted == ["a"] and r.cycle is None, r
+_check(r.sorted == ["a"] and r.cycle is None, r)
 r = topo_sort({"a": ["z"], "z": None})
-assert r.sorted == ["z", "a"] and r.cycle is None, r
+_check(r.sorted == ["z", "a"] and r.cycle is None, r)
 r = topo_sort({"a": None, "b": ["c"], "c": ["b"]})
-assert r.sorted is None and set(r.cycle) == {"b", "c"}, r
+_check(r.sorted is None and set(r.cycle) == {"b", "c"}, r)
 # generator materialisation (must equal list case)
-assert topo_sort({"a": gen()}).sorted == topo_sort({"a": ["b"]}).sorted == ["b", "a"]
+_check(topo_sort({"a": gen()}).sorted == topo_sort({"a": ["b"]}).sorted == ["b", "a"])
 # self-loop unchanged
-assert topo_sort({"a": ["a"]}).cycle == ["a"]
+_check(topo_sort({"a": ["a"]}).cycle == ["a"])
 print("ALL VERIFIED")