improve(ux): improve error message on missing specifications

pyannote/audio/core/model.py

@@ -131,15 +131,7 @@ def specifications(self) -> Union[Specifications, Tuple[Specifications]]:
                 ) from e
 
         else:
-            try:
-                specifications = self.task.specifications
-
-            except AttributeError as e:
-                raise UnknownSpecificationsError(
-                    "Task specifications are not available. This is most likely because they depend on "
-                    "the content of the training subset. Use `model.prepare_data()` and `model.setup()` "
-                    "to go over the training subset and fix this, or let lightning trainer do that for you in `trainer.fit(model)`."
-                ) from e
+            specifications = self.task.specifications
 
         return specifications
 

pyannote/audio/core/task.py

@@ -646,7 +646,11 @@ def setup(self, stage=None):
     def specifications(self) -> Union[Specifications, Tuple[Specifications]]:
         # setup metadata on-demand the first time specifications are requested and missing
         if not hasattr(self, "_specifications"):
-            self.setup()
+            raise UnknownSpecificationsError(
+                "Task specifications are not available. This is most likely because they depend on "
+                "the content of the training subset. Use `task.prepare_data()` and `task.setup()` "
+                "to go over the training subset and fix this, or let lightning trainer do that for you in `trainer.fit(model)`."
+            )
         return self._specifications
 
     @specifications.setter

tests/tasks/test_specifications.py

@@ -0,0 +1,27 @@
+import pytest
+from pyannote.database import FileFinder, get_protocol
+
+from pyannote.audio.core.model import Model
+from pyannote.audio.core.task import UnknownSpecificationsError
+from pyannote.audio.tasks import SpeakerDiarization
+
+
+@pytest.fixture()
+def protocol():
+    return get_protocol(
+        "Debug.SpeakerDiarization.Debug", preprocessors={"audio": FileFinder()}
+    )
+
+
+def test_unknown_specifications_error_raised_on_non_setup_task(protocol):
+    task = SpeakerDiarization(protocol=protocol)
+    with pytest.raises(UnknownSpecificationsError):
+        _ = task.specifications
+
+
+def test_unknown_specifications_error_raised_on_non_setup_model_task(protocol):
+    task = SpeakerDiarization(protocol=protocol)
+    model = Model.from_pretrained("pyannote/ci-segmentation")
+    model.task = task
+    with pytest.raises(UnknownSpecificationsError):
+        _ = model.specifications