如何解决Golang获取google.golang.org/protobuf包报错的问题

今天在重新运行之前的老项目时，报了下面的错误：

# chris @ ChrisdeMacBook-Pro in ~/Go/src/hello [15:11:49]
$ go run main.go
../github.com/golang/protobuf/proto/buffer.go:11:2: cannot find package "google.golang.org/protobuf/encoding/prototext" in any of:
	/usr/local/go/src/google.golang.org/protobuf/encoding/prototext (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/encoding/prototext (from $GOPATH)
../github.com/golang/protobuf/proto/buffer.go:12:2: cannot find package "google.golang.org/protobuf/encoding/protowire" in any of:
	/usr/local/go/src/google.golang.org/protobuf/encoding/protowire (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/encoding/protowire (from $GOPATH)
import cycle not allowed
package main
	imports github.com/astaxie/beego
	imports github.com/prometheus/client_golang/prometheus/promhttp
	imports github.com/prometheus/client_golang/prometheus
	imports github.com/golang/protobuf/proto
	imports google.golang.org/protobuf/proto
	imports google.golang.org/protobuf/proto
../google.golang.org/protobuf/proto/defaults.go:8:2: cannot find package "google.golang.org/protobuf/reflect/protoreflect" in any of:
	/usr/local/go/src/google.golang.org/protobuf/reflect/protoreflect (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/reflect/protoreflect (from $GOPATH)
../google.golang.org/protobuf/proto/extensions.go:15:2: cannot find package "google.golang.org/protobuf/reflect/protoregistry" in any of:
	/usr/local/go/src/google.golang.org/protobuf/reflect/protoregistry (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/reflect/protoregistry (from $GOPATH)
../google.golang.org/protobuf/proto/extensions.go:16:2: cannot find package "google.golang.org/protobuf/runtime/protoiface" in any of:
	/usr/local/go/src/google.golang.org/protobuf/runtime/protoiface (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/runtime/protoiface (from $GOPATH)
../google.golang.org/protobuf/proto/buffer.go:13:2: cannot find package "google.golang.org/protobuf/runtime/protoimpl" in any of:
	/usr/local/go/src/google.golang.org/protobuf/runtime/protoimpl (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/runtime/protoimpl (from $GOPATH)
../github.com/golang/protobuf/ptypes/any/any.pb.go:9:2: cannot find package "google.golang.org/protobuf/types/known/anypb" in any of:
	/usr/local/go/src/google.golang.org/protobuf/types/known/anypb (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/types/known/anypb (from $GOPATH)
../github.com/golang/protobuf/ptypes/duration/duration.pb.go:9:2: cannot find package "google.golang.org/protobuf/types/known/durationpb" in any of:
	/usr/local/go/src/google.golang.org/protobuf/types/known/durationpb (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/types/known/durationpb (from $GOPATH)
../github.com/golang/protobuf/ptypes/timestamp/timestamp.pb.go:9:2: cannot find package "google.golang.org/protobuf/types/known/timestamppb" in any of:
	/usr/local/go/src/google.golang.org/protobuf/types/known/timestamppb (from $GOROOT)
	/Users/chris/Go/src/google.golang.org/protobuf/types/known/timestamppb (from $GOPATH)

# chris @ ChrisdeMacBook-Pro in ~/Go/src/hello [15:11:51] C:1
$

报错信息说的已经很明显了，就是调用包的时候找不到，所以我们需要对应下载。这里具体的操作方法是，从https://github.com/protocolbuffers/protobuf-go/tree/master/ 下载包，放到%GOPATH%\google.golang.org\protobuf下就可以。

mkdir google.golang.org
cd google.golang.org 
git clone https://github.com/protocolbuffers/protobuf-go.git
mv protobuf-go protobuf

此时再次运行之前的启动命令就可以启动项目了～

另外，如果找不到对应google.golang.org包的话， 可以通过访问链接 google.golang.org/protobuf/encoding/prototext 根据提示找到 Index | Files 点击files 就可以找到github相应位置，在执行上面步骤就可以处理掉问题。

End～