It works again. What might be causing this? Please forgive me if this is a basic question, I am new to golang and still trying to get the hang of it. Thanks!
If you are actually trying to use the slug in your handler, then I have a feeling you are trying to set up your routes as if you were working with gorilla/mux which allows slugs to be used as variables passed to your function, so if that’s the case, then have a look at http://www.gorillatoolkit.org/pkg/mux.
The way you have it in the first snippet, AddFeedbackHandler will only be called if the URL path is an exact match for the string /products/feedback/{slug}. http.ServeMux does not support variables in the path; were you expecting {slug} to be treated as a variable?