Errors occured, no packages were upgraded. ⇒ ERROR: Failed to install packages to new root.

LZ用virtualbox安装archlinux，前面的分区什么的问题都是没有的，详情见archwiki安装

按照官方文档执行到（执行命令前，最好到/etc/pacman.d/mirrorlist换个快点的源 国内的话复制下面的Server模板，改一下中间的http://mirrors.163.com/后面跟模板一样）

pacstrap -i /mnt base base-devel

执行玩这个命令之后发现会抛出一个错误

Errors occured, no packages were upgraded. 
⇒ ERROR: Failed to install packages to new root.

百度之后各种方法都不能解决（全是各种贴吧大手子的回复，今天突然注意到是有人回答正确方法的，pacman里面有解决办法，没有看到。。），心灰意冷还是上了Google，第二页找到解决办法，当然此方法可能并不通用，也可贴吧回复的方法只是针对我没用
解决办法如下，执行命令

pacman-key --refresh-keys

官方文档如下（不愧是archwiki）

Note: The archlinux-keyring package, which is a dependency of pacman, contains the latest keys. However keys can also be updated manually using pacman-key –refresh-keys (as root). While doing –refresh-keys, your local key will also be looked up on the remote keyserver, and you will receive a message about it being not found. This is nothing to be concerned about.

ok，问题解决。重新执行

pacstrap -i /mnt base base-devel