fix: three silent fallbacks from tonight now say what they did

Unreadable modality tags widened the erase to every position including
an image span; a partly-failed erase left some scenes changed; an
unreadable sigma disabled sharpening while still reporting it active.
A malformed reference slot claimed nothing was marked.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

movie_editor/backend/builder.py

@@ -628,7 +628,15 @@ def build(object_info: dict, models_config: dict, params: dict, media: dict | No
                     n = int(num)
                 except ValueError:
                     n = 0
-                ref = _reference_by_slot(kind, n) if n > 0 else None
+                if n <= 0:
+                    # A malformed slot is not "no reference marked" — reporting it as that
+                    # sends the user to the Media Bin to fix a value that is wrong in the
+                    # node. Say which it is.
+                    report["unsatisfied"].append(
+                        f"{s.get('node_class')}.{ci_name}: input source '{source}' is not a "
+                        f"reference slot (expected e.g. 'ref#image:1').")
+                    continue
+                ref = _reference_by_slot(kind, n)
                 if ref is None:
                     # Nothing marked in that slot. The socket is simply left unconnected —
                     # an unused reference slot is a normal state, not a setup mistake, so it

movie_editor/tests/test_builder.py

@@ -881,11 +881,14 @@ def test_an_empty_slot_is_not_quietly_filled_with_something_else():
     assert not isinstance(graph["slot_r"]["inputs"].get("ref_images.ref_image0"), list)
 
 
-def test_a_malformed_slot_reference_does_not_crash_the_build():
+def test_a_malformed_slot_says_it_is_malformed_not_that_nothing_is_marked():
+    """"No reference marked" sends the user to the Media Bin to fix a value that is wrong in
+    the node. The two are different problems and must not read the same."""
     _graph, report = builder.build(
         REF_OI, _slot_models(**{"ref_images.ref_image0": "ref#image:nope"}),
         _ref_params(_img("m1", "a.png")))
-    assert not _ref_problems(report)
+    assert any("not a reference slot" in u for u in report["unsatisfied"])
+    assert not any("none marked" in w for w in report["wired"])
 
 
 def test_the_loader_matches_what_the_destination_socket_asks_for():

negative_erase.py

@@ -50,7 +50,13 @@ def _text_positions(meta, length):
             return None          # tags and conditioning disagree — touch nothing selectively
         idx = (flat == 1).nonzero(as_tuple=False).reshape(-1)
         return idx if int(idx.numel()) else None
-    except Exception:
+    except Exception as exc:  # noqa: BLE001
+        # NOT silent: returning None here widens the operation from "text positions only" to
+        # "every position", which on H3 means erasing a text direction out of the reference
+        # image's conditioning. A caller that cannot see this happen cannot explain the
+        # result it gets.
+        print(f"[FunPack] negative_erase: could not read the modality tags ({exc}) — the "
+              f"erase applies to EVERY position, including any image span")
         return None
 
 
@@ -154,7 +160,7 @@ def apply(positive, negative, strength, mode="project", renorm=True):
     if unit is None:
         return positive, "negative_erase: the negative conditioning has no usable direction"
 
-    out, touched = [], 0
+    out, touched, failed = [], 0, []
     for entry in positive:
         try:
             tensor, meta = entry[0], (entry[1] if len(entry) > 1 else {})
@@ -162,8 +168,15 @@ def apply(positive, negative, strength, mode="project", renorm=True):
             if new is not tensor:
                 touched += 1
             out.append((new, meta) + tuple(entry[2:]))
-        except Exception:  # noqa: BLE001
+        except Exception as exc:  # noqa: BLE001
+            failed.append(str(exc))
             out.append(entry)
+    if failed:
+        return positive, (f"negative_erase: {len(failed)} conditioning entr"
+                          f"{'y' if len(failed) == 1 else 'ies'} could not be modified "
+                          f"({failed[0]}) — NOTHING was changed, because a prompt where only "
+                          f"some scenes had the negative removed is worse than one where none "
+                          f"did")
     if not touched:
         return positive, "negative_erase: no conditioning entry could be modified"
     return out, (f"negative_erase: {mode} {float(strength):.2f} on {touched} "

samplers.py

@@ -1379,7 +1379,12 @@ class _SharpenDenoiser:
         denoised = self._inner(x, sigma, **kwargs)
         try:
             s = float(sigma.flatten()[0]) if hasattr(sigma, "flatten") else float(sigma)
-        except Exception:  # noqa: BLE001
+        except Exception as _e:  # noqa: BLE001
+            # Once, not per evaluation — but never nothing. Silently returning here would
+            # leave quality_sharpness switched on, reported as active, and doing nothing for
+            # the whole run.
+            _log.failed("FunPackStudio", "quality sharpness (unreadable sigma)", _e,
+                        "this sampler's steps are NOT being sharpened")
             return denoised
         if s > self._thr:
             # Outside the window: nothing to sharpen, but the prediction is still KEPT. The