Remove proc_macro2::FileName in favor of PathBuf
diff --git a/tests/test.rs b/tests/test.rs
index 5d2fb85..9d37cf3 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -203,7 +203,7 @@
     assert_eq!(end.line, 1);
     assert_eq!(end.column, 0);
     let source_file = Span::call_site().source_file();
-    assert_eq!(source_file.path().to_string(), "<unspecified>");
+    assert_eq!(source_file.path().to_string_lossy(), "<unspecified>");
     assert!(!source_file.is_real());
 }