App deps check

src/cpl-core/cpl/core/configuration/configuration.py

@@ -130,7 +130,7 @@ class Configuration:
         key_name = key.__name__ if inspect.isclass(key) else key
 
         result = cls._config.get(key_name, default)
-        if issubclass(key, ConfigurationModelABC) and result == default:
+        if isclass(key) and issubclass(key, ConfigurationModelABC) and result == default:
             result = key()
             cls.set(key, result)
 

src/cpl-core/cpl/core/configuration/configuration_model_abc.py

@@ -68,7 +68,7 @@ class ConfigurationModelABC(ABC):
             value = cast(Environment.get(env_field, str), cast_type)
 
         if value is None and required:
-            raise ValueError(f"{field} is required")
+            raise ValueError(f"{type(self).__name__}.{field} is required")
         elif value is None:
             self._options[field] = default
             return

src/cpl-core/cpl/core/errors.py

@@ -0,0 +1,15 @@
+import traceback
+
+from cpl.core.console import Console
+
+
+def dependency_error(package_name: str, e: ImportError) -> None:
+    Console.error(f"'{package_name}' is required to use this feature. Please install it and try again.")
+    tb = traceback.format_exc()
+    if not tb.startswith("NoneType: None"):
+        Console.write_line("->", tb)
+
+    elif e is not None:
+        Console.write_line("->", str(e))
+
+    exit(1)