找不到net.Resolver

I have installed go 1.7 in Debian to make doh

It has a Makefile, which triggers the download and install of dependencies into my GOPATH.

The net package is there:

$ ls $GOPATH/src/github.com/golang/net/
AUTHORS         context          dict  http   idna      ipv6     lif      PATENTS       README.md  webdav
bpf             CONTRIBUTING.md  dns   http2  internal  lex      nettest  proxy         route      websocket
codereview.cfg  CONTRIBUTORS     html  icmp   ipv4      LICENSE  netutil  publicsuffix  trace      xsrftoken

Yet during the build, it says it cannot find net.Resolver

$ make
go get -d -v ./doh-client ./doh-server
cd doh-client && go build
# _/home/share/apps/dns-over-https/doh-client
./client.go:47: undefined: net.Resolver
Makefile:46: recipe for target 'doh-client/doh-client' failed
make: *** [doh-client/doh-client] Error 2

This is my first go with go, so I am not sure how it goes about pulling in imports, and whether the Resolver part is present.