It appears there's a fixed set of standard library packages minimock can generate mocks for. For example, go run github.com/gojuno/minimock/cmd/minimock -g -i io.Reader succeeds while the following fails:
$ go run github.com/gojuno/minimock/cmd/minimock -g -i http.ResponseWriter
minimock: -: unknown import path "http": cannot find module providing package http
exit status 1
It appears there's a fixed set of standard library packages
minimock
can generate mocks for. For example,go run github.com/gojuno/minimock/cmd/minimock -g -i io.Reader
succeeds while the following fails: