Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)?

go version go1.10.2 darwin/amd64

What operating system and processor architecture are you using (go env)?

GOARCH="amd64"
GOBIN=""
GOCACHE="/Users/horstrutter/Library/Caches/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="darwin"
GOOS="darwin"
GOPATH="/Users/horstrutter/go"
GORACE=""
GOROOT="/Users/horstrutter/gotip"
GOTMPDIR=""
GOTOOLDIR="/Users/horstrutter/gotip/pkg/tool/darwin_amd64"
GCCGO="gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/var/folders/54/ctlrqd1s2vz28g2m8_psscyc0000gn/T/go-build797093095=/tmp/go-build -gno-record-gcc-switches -fno-common"

What did you do?

I noted some strange behaviour:

go get -u golang.org/x/crypto/... works!

but cloning does not and I wonder why:

git clone https://golang.org/x/crypto crypto Cloning into 'crypto'... fatal: https://golang.org/x/crypto/info/refs not valid: is this a git repository?

Looks like I get the same error when trying to clone any other repo from https://golang.org/x
at least for vgo I get the same.

What am I doing wrong here?