Fixes

src/ert/config/ert_config.py

@@ -319,14 +319,19 @@ def from_dict(cls, config_dict) -> Self:
                     config_dict[ConfigKeys.SUMMARY] = [summary_keys] + [
                         [key] for key in summary_obs if key not in summary_keys
                     ]
+            if model_config:
                 observations = cls._create_observations(
                     obs_config_content,
                     ensemble_config,
                     model_config.time_map,
                     model_config.history_source,
                 )
             else:
-                observations = None
+                errors.append(
+                    ConfigValidationError(
+                        "Not possible to validate observations without valid model config"
+                    )
+                )
         except ConfigValidationError as err:
             errors.append(err)
 

tests/ert/unit_tests/config/test_ert_config.py

@@ -11,7 +11,7 @@
 import pytest
 from hypothesis import assume, given, settings
 from hypothesis import strategies as st
-from pydantic import RootModel, TypeAdapter, ValidationError
+from pydantic import RootModel, TypeAdapter
 
 from ert.config import AnalysisConfig, ConfigValidationError, ErtConfig, HookRuntime
 from ert.config.ert_config import site_config_location
@@ -1469,7 +1469,7 @@ def test_no_timemap_or_refcase_provides_clear_error():
             print(line, end="")
 
     with pytest.raises(
-        ValidationError,
+        ConfigValidationError,
         match="Missing REFCASE or TIME_MAP for observations: WPR_DIFF_1",
     ):
         ErtConfig.from_file("snake_oil.ert")
@@ -1510,7 +1510,7 @@ def test_that_multiple_errors_are_shown_when_generating_observations():
                 continue
             print(line, end="")
 
-    with pytest.raises(ValidationError) as err:
+    with pytest.raises(ConfigValidationError) as err:
         _ = ErtConfig.from_file("snake_oil.ert")
 
     expected_errors = [