We might want to add some sort of http-error-behaviour option to the config which lets you select how to handle HTTP errors. Some possible strategies are:

• AlwaysFail - translates all non-2XX status codes to a failure
• Warn - translates all non-2XX status codes to a warning
• WarnOnServerError - translates status codes which indicate there was a spurious server failure to warnings. All other non-2XX status codes are errors.
• ...

Original comment from rust-lang/rustc-dev-guide#388 (comment):

@Michael-F-Bryan I think it would be helpful to be able to not fail the build for certain types of errors. For example, a 404 should definitely fail the build, whereas a time out, 429 (too many requests), or 50x (internal error) should not fail the build.