config.nix validation?

Should the values from config.nix be validated in any way? They are obviously trusted, but it is very easy for the users to make mistakes that could cause extremely confusing problems. For instance, the update patch doesn't support URLs with a query string or a fragment specifier. In fact, such URLs could get mangled. There are other URLs that tools like curl will accept but which will break the build. Should these be validated with regular expressions before use? That will result in build-time errors that at least somewhat point to the source of the problem, rather than mysterious build-time or runtime misbehavior. -- Sincerely, Demi Marie Obenour (she/her/hers)