Improve UnknownQualifiedServiceRequestedError message

test/unit/test_container.py

@@ -300,7 +300,7 @@ def inner(_sub1: FooBase = Inject(qualifier="sub1")): ...
 
         self.assertIn(
             "Cannot instantiate concrete class for <class 'test.fixtures.FooBase'> "
-            "as qualifier 'sub1' is unknown. Available qualifiers: set()",
+            "as qualifier 'sub1' is unknown. Available qualifiers: []",
             str(context.exception),
         )
 
@@ -315,7 +315,7 @@ def inner(_sub1: FooBase): ...
 
         self.assertEqual(
             f"Cannot instantiate concrete class for {FooBase} as qualifier 'None' is unknown. "
-            "Available qualifiers: {'foobar'}",
+            "Available qualifiers: ['foobar'].",
             str(context.exception),
         )
 
@@ -329,7 +329,7 @@ def inner(_sub1: FooBase): ...
 
         self.assertEqual(
             f"Cannot instantiate concrete class for {FooBase} as qualifier 'None' is unknown. "
-            "Available qualifiers: set()",
+            "Available qualifiers: [].",
             str(context.exception),
         )
 
@@ -345,7 +345,7 @@ def inner(_foo: RegisterWithQualifierClass): ...
 
         self.assertIn(
             f"Cannot instantiate concrete class for {RegisterWithQualifierClass} "
-            f"as qualifier 'None' is unknown. Available qualifiers: {{'{__name__}'}}",
+            f"as qualifier 'None' is unknown. Available qualifiers: ['{__name__}'].",
             str(context.exception),
         )
 

wireup/errors.py

@@ -68,10 +68,11 @@ def __init__(
     ) -> None:
         self.klass = klass
         self.qualifier = qualifier
+        qualifiers_str = ", ".join(sorted(f"'{q}'" for q in available_qualifiers))
 
         super().__init__(
             f"Cannot instantiate concrete class for {klass} as qualifier '{qualifier}' is unknown. "
-            f"Available qualifiers: {available_qualifiers}",
+            f"Available qualifiers: [{qualifiers_str}].",
         )