搭建 Go 的开发环境时，我们都需要先安装 go 的安装包，在 windows 下，会自动配置 GOPATH 环境变量。
使用 vscode 开发 go在 vscode 中新建了一个 go 文件后，vscode 会提示安装go插件
点击install all 后，即使上网的姿势很科学，可能也会安装失败，提示
Installing github.com/mdempsky/gocode FAILED Installing github.com/uudashr/gopkgs/v2/cmd/gopkgs FAILED Installing github.com/ramya-rao-a/go-outline FAILED Installing github.com/acroca/go-symbols FAILED Installing golang.org/x/tools/cmd/guru FAILED Installing golang.org/x/tools/cmd/gorename FAILED Installing github.com/cweill/gotests/… FAILED Installing github.com/fatih/gomodifytags FAILED Installing github.com/josharian/impl FAILED Installing github.com/davidrjenni/reftools/cmd/fillstruct FAILED Installing github.com/haya14busa/goplay/cmd/goplay FAILED Installing github.com/godoctor/godoctor FAILED Installing github.com/go-delve/delve/cmd/dlv FAILED Installing github.com/stamblerre/gocode FAILED Installing github.com/rogpeppe/godef FAILED Installing github.com/sqs/goreturns FAILED Installing golang.org/x/lint/golint FAILED
原因不明，但是有办法解决。
在这种情况下，我们需要 go mod 代理来安装
go env -w GO111MODULE=on go env -w GOPROXY=https://goproxy.io,direct
重新打开 vscode，点击 install all，即可安装成功
