Scribunto error messages in English Wiktionary have a popup that appears when you click them. The popup contains more information on the error. Sometimes this involves a traceback.
When the traceback mentions a line in a Lua module on the wiki, it links to the module, with a link fragment containing the line number; for instance, `#mw-ce-l174` where 174 is the line of the module mentioned in that line of the traceback. If you click the link, and you go to the module, but the fragment has no effect. This seems to happen whether or not CodeEditor is enabled.
Formerly, when you got to the module page, the textbox would be focused and in this example the cursor would be placed at the beginning of the line mentioned in the link fragment. This was very helpful because you would be able to see the line mentioned without having to scroll down in the textbox or use the "jump to line" feature.
I don't recall exactly when this changed, but a year or more ago.