You would be interested in this if you need the 'crypto' library to work in a FIPS 140-2 compliant way. You can switch on / off this mode by setting the runtime variable GOFIPS=1 before running your Go program [1]. Nice.
It looks like the Go community officially has no plans to support FIPS140-2 any time, so I'm glad to see this alternative.
[1] https://github.com/microsoft/go/tree/microsoft/main/eng/doc/...