Checksum verification behaviour mismatch with other proxies about goproxy HOT 2 CLOSED

Hi @silverwind sumdb service is a append only service, the checksum of a module will be recored when the sumdb service first meet the module, but some repo authors may change the tag (retag).

The first two proxies always keep (cached) the old zip module package, so the checksum is same with sum.golang.org.
but goproxy.io cached the latest module package.

from goproxy.

I'm using the athens proxy now and there, I have been able to solve the issue by having the proxy download via the official proxy, e.g. a chain of two proxies:

gomods/athens#1696 (comment)

I think this is a common enough error that you may want to consider having an option for this as well on this proxy. There are probably thousands of affected packages.

from goproxy.