It's so that you can have a seamless module version checksum [1]. The checksum in proxy ensures that you don't "trust on first use" whenever you update a module

It's so that you can have a seamless module version checksum [1]. The checksum in proxy ensures that you don't "trust on first use" whenever you update a module. [1] https://go.googlesource.com/proposal/+/master/design/25530-sumdb.md https://go.googlesource.com/proposal/+/master/design/25530-s...