今天在Linux下安装Zgrab的时候，当执行最后一步命令“make"的时候，报错如下：
cd cmd/zgrab2 && go build && cd ../..
../../lib/ssh/kex.go:22:2: cannot find package "golang.org/x/crypto/curve25519" in any of:
/usr/local/go/src/golang.org/x/crypto/curve25519 (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/crypto/curve25519 (from $GOPATH)
../../lib/ssh/keys.go:28:2: cannot find package "golang.org/x/crypto/ed25519" in any of:
/usr/local/go/src/golang.org/x/crypto/ed25519 (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/crypto/ed25519 (from $GOPATH)
../../lib/smb/ntlmssp/crypto.go:9:2: cannot find package "golang.org/x/crypto/md4" in any of:
/usr/local/go/src/golang.org/x/crypto/md4 (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/crypto/md4 (from $GOPATH)
../../../../../golang.org/x/net/idna/idna10.0.0.go:25:2: cannot find package "golang.org/x/text/secure/bidirule" in any of:
/usr/local/go/src/golang.org/x/text/secure/bidirule (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/text/secure/bidirule (from $GOPATH)
../../../../../golang.org/x/net/idna/idna10.0.0.go:26:2: cannot find package "golang.org/x/text/unicode/bidi" in any of:
/usr/local/go/src/golang.org/x/text/unicode/bidi (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/text/unicode/bidi (from $GOPATH)
../../../../../golang.org/x/net/idna/idna10.0.0.go:27:2: cannot find package "golang.org/x/text/unicode/norm" in any of:
/usr/local/go/src/golang.org/x/text/unicode/norm (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/text/unicode/norm (from $GOPATH)
../../lib/http/request.go:31:2: cannot find package "golang.org/x/text/width" in any of:
/usr/local/go/src/golang.org/x/text/width (from $GOROOT)
/usr/local/go/bin/src/golang.org/x/text/width (from $GOPATH)
../../modules/mongodb/scanner.go:9:2: cannot find package "gopkg.in/mgo.v2/bson" in any of:
/usr/local/go/src/gopkg.in/mgo.v2/bson (from $GOROOT)
/usr/local/go/bin/src/gopkg.in/mgo.v2/bson (from $GOPATH)
../../modules/redis/scanner.go:27:2: cannot find package "gopkg.in/yaml.v2" in any of:
/usr/local/go/src/gopkg.in/yaml.v2 (from $GOROOT)
/usr/local/go/bin/src/gopkg.in/yaml.v2 (from $GOPATH)
make: *** [Makefile:24：zgrab2] 错误 1
解决方法
我在上面的错误代码已经用绿色标记出来了，其根本原因就是以上这些包找不到仅此而已，解决方法也非常的简单。
由于各种原因，国内使用 go get 安装 golang 官方包会失败，我们必须手工去github下载这些包了。
具体解决方法如下：
cd /usr/local/go/bin/src/golang.org/x #go的安装目录，替换成自己的即可
git clone https://github.com/golang/crypto.git
git clone https://github.com/golang/text.git
go get gopkg.in/mgo.v2/bson
go get gopkg.in/yaml.v2简单给大家延伸一点知识：gopkg.in是Go语言的稳定API；
gopkg.in服务提供了版本化的URL，这些URL提供了正确的元数据，用于将go工具重定向到定义良好的GitHub存储库。强烈建议选择使用此服务的开发人员不要在不更改包URL中的版本的情况下进行任何向后不兼容的更改。此约定提高了依赖代码继续工作的机会，同时依赖于包的发展。
使用gopkg.in的优点是URL更干净，更短，在使用浏览器打开时重定向到godoc.org上的包文档，处理git分支和标签以进行版本控制，最重要的是鼓励采用稳定版本化的API 。
请注意，gopkg.in不包含包代码。相反，go工具被重定向并直接从相应的GitHub存储库获取代码。
yaml该软件包的实际实现是在GitHub中：https://github.com/go-yaml/yaml
如果还有其它的包，原理同上，只需要直接去“https://github.com/golang/”这个地址手工克隆下载到本地就可以了。
