cannot find package golang.org/x/crypto/ripemd160

cd $GOPATH/src/
如果没有golang/x 创建mkdir -p golang/x，然后cd golang/x

git clone https://github.com/golang/crypto.git

就可以了

示例：

cannot find package "golang.org/x/net/context" in any of:

        /usr/local/go/src/golang.org/x/net/context (from $GOROOT)
        /root/go/src/golang.org/x/net/context (from $GOPATH)

git clone --depth=1 ​​https://github.com/golang/xxx.git​​

这种方法就可以了，github是可以正常使用的。