Alternating prompts: say whether the prompt had no options or no named step was in the run

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

modules/conditioning/prompt_alternatives/__init__.py

@@ -71,17 +71,18 @@ def install(patcher, values, key):
     steps = {**{i - 1: 1 for i in b if i >= 1}, **{i - 1: 0 for i in a if i >= 1}}      # step index -> option; A wins an overlap
     if not steps:
         return None
-    live = {"cache": {}, "used": 0}
+    live = {"cache": {}, "used": 0, "seen": False}
 
     def start(executor, *args, **kwargs):
-        live["cache"], live["used"] = {}, 0
+        live["cache"], live["used"], live["seen"] = {}, 0, False
         try:
             return executor(*args, **kwargs)
         finally:
             live["cache"].clear()
             if not live["used"]:
-                _say("Inactive | no step of this run read an option (needs [A|B] in the prompt, "
-                     "and steps inside the schedule)")
+                _say("Inactive | the prompt had no [A|B] options (a bare A|B counts only between two shortcuts)"
+                     if not live["seen"] else
+                     "Inactive | none of the steps named here is a step of this run")
 
     patcher.add_wrapper_with_key(WrappersMP.OUTER_SAMPLE, key, start)
 
@@ -90,6 +91,7 @@ def install(patcher, values, key):
         to = named.get("transformer_options") or {}
         where = dit_hooks.current_step(to)
         simul, context = to.get(SIMUL), named.get("c_crossattn")
+        live["seen"] = live["seen"] or bool(simul)
         if (not simul or where is None or where[0] not in steps or to.get(streams.OPTION_PINNED)
                 or dit_hooks.probing(to) or any(int(i) != 0 for i in (to.get("cond_or_uncond") or [0]))):
             return executor(x, t, *args, **kwargs)

modules/sampling/noise_merge/tests/test_through_the_app.py

@@ -235,3 +235,20 @@ def test_a_merged_step_wins_over_an_assigned_step(server, model):
     finally:
         hook.remove()
     assert len(seen) == 5 and not torch.allclose(seen[1], seen[2])           # step 2 made two calls: A, then B
+
+
+def test_alternating_prompts_say_why_they_did_nothing(server, model):
+    """No [A|B] in the prompt, or no named step in the run: two different sentences."""
+    from comfy.nested_tensor import NestedTensor
+    from core import log
+    from modules.sampling.modifiers.nodes import FunUILoadModifiers, FunUIModifierSettings
+    from modules.sampling.sampler.nodes import FunUISampler
+    shapes = NestedTensor((torch.zeros(1, 24, 2, 4, 4), torch.zeros(1, 32, 2, 3)))
+    cond = [[torch.randn(1, 5, 48), {}]]
+    checked = FunUIModifierSettings.execute(_saved_by_the_app(server, dict(
+        APP_VALUES, noise_merge={"enabled": False}, prompt_alternatives={"separate": True, "b_steps": "1"}))).result[0]
+    patched, _ = FunUILoadModifiers.execute(model, checked).result
+    log._reset()
+    FunUISampler.execute(patched, cond, cond, {"samples": shapes}, seed=1, steps=3, cfg=1.0,
+                         sampler_name="lcm", scheduler="beta", denoise=1.0)
+    assert any("the prompt had no [A|B] options" in e["message"] for e in log.history())