fix[ux]: improve initializer hint for unimported modules (#4145)

improve initializer hint in the case that the needed module is not
already imported

tests/functional/syntax/modules/test_initializers.py

@@ -1273,7 +1273,7 @@ def foo():
     assert e.value._hint == "add `lib3 := lib3` to its initializer list"
 
 
-def test_hint_for_missing_initializer_when_no_import(make_input_bundle):
+def test_hint_for_missing_initializer_when_no_import(make_input_bundle, chdir_tmp_path):
     lib1 = """
 counter: uint256
     """
@@ -1297,7 +1297,8 @@ def foo():
     with pytest.raises(InitializerException) as e:
         compile_code(main, input_bundle=input_bundle)
     assert e.value._message == "`lib2` uses `lib1`, but it is not initialized with `lib1`"
-    assert e.value._hint == "try importing lib1 first"
+    hint = "try importing `lib1` first (located at `lib1.vy`)"
+    assert e.value._hint == hint
 
 
 @pytest.fixture

vyper/semantics/analysis/module.py

@@ -514,7 +514,8 @@ def visit_InitializesDecl(self, node):
                     break
 
             if rhs is None:
-                hint = f"try importing {item.alias} first"
+                hint = f"try importing `{item.alias}` first "
+                hint += f"(located at `{item.module_t._module.path}`)"
             elif not isinstance(annotation, vy_ast.Subscript):
                 # it's `initializes: foo` instead of `initializes: foo[...]`
                 hint = f"did you mean {module_ref.id}[{lhs} := {rhs}]?"