找不到来自$GOROOT和$GOPATH的包

Question

在尝试运行go build命令后，我得到了一小部分错误

go build ./...
trillian.pb.go:7:8: cannot find package "github.com/golang/protobuf/proto" in any of:
    /usr/local/go/src/github.com/golang/protobuf/proto (from $GOROOT)
    /Projects/Proj1/trillian/src/github.com/golang/protobuf/proto (from $GOPATH)

trillian.pb.go:11:8: cannot find package "github.com/golang/protobuf/ptypes/any" in any of:
    /usr/local/go/src/github.com/golang/protobuf/ptypes/any (from $GOROOT)
    /Projects/Proj1/trillian/src/github.com/golang/protobuf/ptypes/any (from $GOPATH)

trillian_admin_api.pb.go:12:8: cannot find package "github.com/golang/protobuf/ptypes/empty" in any of:
    /usr/local/go/src/github.com/golang/protobuf/ptypes/empty (from $GOROOT)
    /Projects/Proj1/trillian/src/github.com/golang/protobuf/ptypes/empty (from $GOPATH)

trillian.pb.go:10:8: cannot find package "github.com/google/trillian/crypto/sigpb" in any of:
    /usr/local/go/src/github.com/google/trillian/crypto/sigpb (from $GOROOT)
    /Projects/Proj1/trillian/src/github.com/google/trillian/crypto/sigpb (from $GOPATH)

trillian_admin_api.pb.gw.go:17:2: cannot find package "github.com/grpc-ecosystem/grpc-gateway/runtime" in any of:
    /usr/local/go/src/github.com/grpc-ecosystem/grpc-gateway/runtime (from  $GOROOT)
    /Projects/Proj1/trillian/src/github.com/grpc-ecosystem/grpc-gateway/runtime (from $GOPATH)

trillian_admin_api.pb.gw.go:18:2: cannot find package "github.com/grpc-ecosystem/grpc-gateway/utilities" in any of:
    /usr/local/go/src/github.com/grpc-ecosystem/grpc-gateway/utilities (from $GOROOT)
    /Projects/Proj1/trillian/src/github.com/grpc-ecosystem/grpc-gateway/utilities (from $GOPATH)

trillian_admin_api.pb.go:15:2: cannot find package "golang.org/x/net/context" in any of:
    /usr/local/go/src/golang.org/x/net/context (from $GOROOT)
    /Projects/Proj1/trillian/src/golang.org/x/net/context (from $GOPATH)

trillian_admin_api.pb.go:10:8: cannot find package "google.golang.org/genproto/googleapis/api/annotations" in any of:
    /usr/local/go/src/google.golang.org/genproto/googleapis/api/annotations (from $GOROOT)
    /Projects/Proj1/trillian/src/google.golang.org/genproto/googleapis/api/annotations (from $GOPATH)

trillian_log_api.pb.go:65:8: cannot find package "google.golang.org/genproto/googleapis/rpc/status" in any of:
    /usr/local/go/src/google.golang.org/genproto/googleapis/rpc/status (from $GOROOT)
    /Projects/Proj1/trillian/src/google.golang.org/genproto/googleapis/rpc/status (from $GOPATH)

trillian_admin_api.pb.go:11:8: cannot find package "google.golang.org/genproto/protobuf/field_mask" in any of:
    /usr/local/go/src/google.golang.org/genproto/protobuf/field_mask (from $GOROOT)
    /Projects/Proj1/trillian/src/google.golang.org/genproto/protobuf/field_mask (from $GOPATH)

转到环境输出

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/Projects/Proj1/trillian"
GORACE=""
GOROOT="/usr/local/go"
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build690359699=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"

虽然设置了GOPATH和GOROOT，但仍然无法正常运行该命令。尝试安装到主目录和自定义目录，更改gopath和goroot，但仍然没有成功。有什么建议如何解决这个问题吗？

Answer 1

所有导入的包首先在GOROOT和GOPATH环境变量中查找。确保您的包位于这些目录下的某个位置。

现在假设测试项目设置为:/Users/test/Desktop/GoProject.

和GOROOT : /usr/local/go (安装go的位置)。如果您的GoProject中的某个文件具有导入为

import "abc/def/packageName"

则它应该出现在以下两个位置中的任意一个：

/Users/test/Desktop/GoProject/src/abc/def/packageName/* /usr/local/go/src/abc/def/packageName/*

如果没有，您将收到问题中报告的错误。

这些目录中的文件的第一行如下

package packageName

声明所有这些文件构成了一个包packageName

Answer 2

正如官方文件所说：

最简单的方法是运行go get -u github.com/golang/protobuf/{proto,protoc-gen-go}。

在这里查看完整的介绍:golang/protobuf installation。

Answer 3

确保有一个版本的go 1.11+。

较旧的版本不支持模块，因此无法下载所需的内容，从而导致Can't find package from $GOROOT and $GOPATH问题。