ARCH LINUX pacman更新错误：gcc requires gcc-libs=4.7.0-3

arch更新pacman -Syu出现如下错误 

pacman -Syu

:: Synchronising package databases...
 core is up to date
 extra is up to date
 community is up to date
:: The following packages should be upgraded first :
    pacman
:: Do you want to cancel the current operation
:: and upgrade these packages now? [Y/n] y

resolving dependencies...
looking for inter-conflicts...
error: failed to prepare transaction (could not satisfy dependencies)
:: gcc: requires gcc-libs=4.7.0-3

 用pacman -Qs gcc-libs查看下有没有gcc-libs 4.7.0-3

pacman -Qs gcc-libs
 
local/gcc-libs 4.7.0-3 (base)
    Runtime libraries shipped by GCC

gcc-libs 4.7.0-3是存在的

用pacman把pacman自己升级一下

pacman -S pacman

升级完再更新

pacman -S pacman

没报错，可以正常更新。