方法1、从github下载然后软连:

git clone https://github.com/golang/sys.git $GOPATH/src/github.com/golang/sys
git clone https://github.com/golang/net.git $GOPATH/src/github.com/golang/net
git clone https://github.com/golang/text.git $GOPATH/src/github.com/golang/text
git clone https://github.com/golang/lint.git $GOPATH/src/github.com/golang/lint
git clone https://github.com/golang/tools.git $GOPATH/src/github.com/golang/tools
git clone https://github.com/golang/crypto.git $GOPATH/src/github.com/golang/crypto


ln -s $GOPATH/src/github.com/golang/ $GOPATH/src/golang.org/x

git clone https://github.com/grpc/grpc-go.git $GOPATH/src/google.golang.org/grpc
git clone https://github.com/golang/net.git $GOPATH/src/golang.org/x/net
git clone https://github.com/golang/text.git $GOPATH/src/golang.org/x/text
go get -u github.com/golang/protobuf/{proto,protoc-gen-go}
git clone https://github.com/google/go-genproto.git $GOPATH/src/google.golang.org/genproto

cd $GOPATH/src/
go install google.golang.org/grpc

方法2、使用go mod修改

go mod edit -replace=golang.org/x/sync@v0.0.0-20180314180146-1d60e4601c6f=github.com/golang/sync@v0.0.0-20180314180146-1d60e4601c6f
go mod edit -replace=golang.org/x/sys@v0.0.0-20180909124046-d0be0721c37e=github.com/golang/sys@v0.0.0-20180909124046-d0be0721c37e
go mod edit -replace=golang.org/x/net@v0.0.0-20180906233101-161cd47e91fd=github.com/golang/net@v0.0.0-20180906233101-161cd47e91fd
go mod edit -replace=golang.org/x/text@v0.3.0=github.com/golang/text@v0.3.0
go mod edit -replace=golang.org/x/crypto@v0.0.0-20170930174604-9419663f5a44=github.com/golang/crypto@v0.0.0-20170930174604-9419663f5a44

go mod edit -replace=google.golang.org/genproto@v0.0.0-20190201180003-4b09977fb922=github.com/google/go-genproto@v0.0.0-20190201180003-4b09977fb922
go mod edit -replace=google.golang.org/grpc@v1.18.0=github.com/grpc/grpc-go@1.18.0