trigger rustdoc-gui error

Author: lucarlig

tests/rustdoc-gui/anchor-navigable.goml

@@ -8,4 +8,4 @@ go-to: "file://" + |DOC_PATH| + "/test_docs/struct.Foo.html"
 // We check that ".item-info" is bigger than its content.
 move-cursor-to: ".impl"
 assert-property: (".impl > a.anchor", {"offsetWidth": "8"})
-assert-css: (".impl > a.anchor", {"left": "-8px"})
+assert-css: (".impl > a.anchor", {"left": "-888px"})