Problem with homebrew recipe for ctags
HTTP 404 Error: Not found. This means the URL referenced something that no longer exists at that location. The problem isn't with curl, the problem is with the homebrew recipe for ctags -- it's out of date.

You can see this for yourself by pointing a browser to the patch URL that the homebrew recipe is trying to the URL that curl is trying to download from: https://raw.github.com/gist/4010022/8d0697dc87a40e65011e2192439609c17578c5be/ctags.patch

You get a 404 Not Found error from GitHub.

Try updating your recipes, it's likely the ctags recipe is out of date:

brew update


If that doesn't resolve the problem, report it as an issue for the ctags recipe here: https://github.com/Homebrew/homebrew/issues